From War to Science
by Emotistic Optimistic
Summary: This would have been a called a look into a mysterious man's past, but the mystery is lost when everyone forgets that he even existed. (A sort-of prequel to Reset.)
1. War

**Part 1: The Refuge**

* * *

In retrospect, they should have seen it coming.

Tensions had been growing between the monsters and the humans, and they had been lucky to keep out of most of the trouble. Skeletons were, truth be told, in a funny place. After all, humans also had skeletons, but it was more a _part_ of them rather than their whole being. Not to mention that theirs were much more solid; the skeletons in the village had a similar makeup to monsters: magic and dust. How it came to be that way, no one knew, and so long as they had their security from the war, there was no reason for them to question it. They were a strange mixture of monster and human, and both sides of the war seemed to recognize that and let them be.

But, of course, the humans were the ones to ruin that.

* * *

He was particularly unlucky. He was born into the Gaster clan. At home, he regularly impressed his family with his articulacy and turns of phrase. He was good at telling stories, and every now and again he would manage a good joke.

In the village, he was useless.

You see, his particularly family tree had a strange quirk. While most skeletons had particular cadences and phrases common only to their clans—with enough variance that they needed a "common" dialect—the Gasters went above and beyond: they _signed_ their language. The story was that several of their ancestors had been mute, but he suspected it was more out of defiance rather than necessity. Regardless, it made any trip to the village a nightmare. He could manage a few bits of garbled Arial, enough to get what he needed, but ultimately he was left silent, too proud to admit that languages did not come naturally to him.

In later years, he would regret not trying harder to learn. It might have made all the difference.

It was the smell of smoke that woke him that morning, and the cries from the village that got him out of bed. His sockets were wide with horror as he saw the scene outside his window—smoke pouring from windows, roofs licked with flames, skeletons running for cover as an army of humans swarmed their village. Some fought back, but by the time he tore himself away, the ground was already powdered white with dust.

They needed to get out.

He ran through the house, already in silent chaos. His mother was signing comforting things to his sisters, his father's hands moving steadily as he came up with a plan of attack. Enough of them could fight, so they would defend the ones that couldn't. Hopefully the clan could make it to the forest, and after that—

He'd never been certain about the noises his family could make. As the wall to their house collapsed, crushing his father beneath it mid-sign, he found that screaming was one of them.

A wave of humans came through the new opening, their magicians and warriors already attacking. Without thinking, he shot a slew of bones at the human nearest to him.

Oh, _god._

Humans _splatter._

He had no time to be horrified by the blood covering him. His attack had rendered them even more dangerous in the human's eyes, and the slaughter truly begun. He shot as many bones as he could, impaling a few humans, but not nearly enough. More and more dust filled the air, clinging to him, coating his bones and clothing. As he squinted through the clouds of dust and smoke, he caught a glimpse of his mother's hand, signing one thing.

 _Run._

His legs moved faster than his mind—before he knew what exactly he was doing, he was pushing himself out of the house. He ran through the village, toward the forest. He threw bones at every human in his way, clambering through the wreckage. More dust, more smoke, more blood. It all stuck to him, burning his sockets and sticking to his ribs. A small part of him said it would be better to give up, to not have to live through this nightmare, but the survival instinct was far too great.

Eventually, he was out of the village, though the screams still echoed against the trees. He shut his sockets and leaned against a tree, taking gulps of air as his skull spun. Could a skeleton vomit? He felt as if he might.

The crack of a stick breaking echoed in the forest, and once again he was tensed, bones at the ready. His breath caught as he saw glowing blue eyes in the growing darkness. A woman's voice shouted something he couldn't quite understand, and the blue slowly faded. He swallowed and took a cautious step forward.

Two skeletons stood in front of him—one short and one fairly tall. Their clothes were powdered with dust, just as his were, and they looked just as haunted as he felt.

His arms went limp, and they whispered to each other. Finally, the woman asked him something. He grimaced and signed back, _I don't understand you._

The man murmured something to the woman, then asked, "Arial?"

He hesitated. "A little."

"What's - name? - Lucida…" The man gestured to the woman, who waved, then to himself. "…and Palatino."

He blinked. He'd never heard his name aloud. He signed it to them. Palatino frowned, but Lucida pat his humerus and looked back up at him.

"- - going to - - some- safe. You - come - us."

He translated what he could and guessed the rest. After a moment, he nodded. If this was all that was left, they needed to stay together.

Lucida smiled at him—in times of peace, he was certain it would be a wide, lovely smile—then took Palatino's arm. Palatino looked him over again, then nodded and turned. They headed deeper into the forest.

* * *

"Lu-ci-da."

"Lu-ci-da."

"Pal-a-ti-no."

"Pal-a-ti-no."

"Tree."

"Tree."

"See? Easy!"

Night had come. Sufficiently deep in the forest, they had set up camp, and Lucida was trying her hardest to teach him Arial. But…she really wasn't that great of a teacher; her method of teaching involved pointing at things and saying them slowly for him to repeat. But she was _so_ eager, and at any rate, it wasn't like he could tell her it wasn't helping. Finally, after about an hour of him parroting her, it was Palatino who had the idea of writing their respective alphabets in the dirt.

With some hesitation, he scrawled out the strange symbols of his written language—again, the Gasters went above and beyond when it came to isolating linguistics. The couple—he _thought_ he had picked up something about them being recently married? But it was entirely likely he had misunderstood—looked over it, and Palatino wrote the Arial alphabet under each symbol.

"- what's - name? Point."

His browbone furrowed, and he used the stick he'd written with to point at the letters.

W-I-N-G. D-I-N-G.

"Wing Ding?" Lucida was politely trying to conceal a laugh.

He pulled a face. It was a much more graceful name when signed. Palatino rolled his own stick in his hands.

"- right, Wing…or, uh, do you - Ding?"

He grimaced again. Neither sounded right. He tapped on two letters.

"W.D.?"

He nodded. Still not great, but it would suffice. Palatino spoke, but it was muffled by static filling his skull. It was entirely possible he'd never see his name signed again. His family was gone—the dust on his clothes was proof. He felt his ribs constrict, and he couldn't breathe as the realization of the past few hours hit him full force. He was the last of his clan…he had watched his family _die._

"W.D.? _W.D.! Wing Ding!_ "

He gasped in a breath, brought back to the present. Lucida and Palatino were staring hard at him, their sockets wide with concern. He let out another breath and quickly signed that he was fine, then stopped himself and instead said, "Fine. It fine."

A silence stretched between the three skeletons. No doubt the couple were having the same thoughts as him. Finally, though, it was he who spoke first.

"Monsters. Go to…monsters," he managed to say, with no small amount of difficulty. "Erm…they…erm…ready?" He looked up at them hopelessly. Both skeletons frowned at him, but it was Lucida who put his words together. She spoke excitedly to Palatino, who remained silent for a long stretch. Finally, he nodded.

"Tomorrow - go to - monster's -."

Wing Ding Gaster let out a breath. Perhaps they would find safety with the monsters. Perhaps they could stop the humans.

He could hope, at least.


	2. Battle

By the time they reached the edge of the forest, there were five in their group—a very young girl and a very old man had joined halfway through the night. He couldn't help but think what a sorry group this was—and _this_ was all that was left of their village. But there was no time to wallow, no time to grieve. They needed to reach the monsters' kingdom by nightfall, lest they be ambushed.

Lucida, despite everything, chattered away as they walked. Though strained, her voice still carried a note of optimism in it; her words must have been even more so. Even though W.D. couldn't understand a word of what she said—he _suspected_ it was Serif, but how could he know—he had to admire her tenaciously upbeat attitude. Palatino and the other two remained silent; W.D. had tried to sign "hello" to the old man, but the blank look on his face said far more than his hands could. W.D. stilled his hands for the rest of the walk, instead focusing on potential threats as they made their way through the forest.

The last of the Gasters was good enough for that, at least.

Luckily enough, they reached the Monster Kingdom before the sun had set. The small group drew even closer together as they entered the borders: the old man carrying the girl and Palatino's arm protectively around Lucida. Already, the city—well, really, little more than a village—was bustling with activity. No doubt word had spread about the attack on the skeleton village. They knew the humans were coming. Even so, the odd monster would send a suspicious glare their way—after all, it could only be assumed that skeletons were in some way related to humans. But there was no time to waste worrying over a relatively minor threat; if the monsters wanted the slightest chance of surviving this last battle—and it _would_ be the last, they all knew—they needed to work quickly.

W.D. watched with a furrowed browbone as monsters either dashed in houses or prepared their magic. Even so, the energy didn't seem…right. There was not the frenzy of fear that had been in the village. Just…reluctance? Of course, there was the chance that he wasn't reading them right; he didn't know much about monster culture or warfare, to be honest. But…one thing he _did_ know is that monsters did not like fighting.

That was a purely _human_ trait.

A loud voice echoed through the streets, speaking with urgency. He looked back at the other skeletons, who, surprisingly, looked just as confused as he felt. Oh, of course. Monsters didn't speak Arial. Now they were all just as lost as he was.

He stepped back as the monsters around them charged forward. A call to arms, then. W.D. looked after the last few to run forward, then glanced back at the little group. He clenched his jaw, then turned to follow after the monsters. He heard Palatino and Lucida call for him, but he kept running. He had to help. He _could not_ stand idly by during this. Not with these murderers coming for more death.

He reached the edge of the city, swallowing as he saw the distant smoke of his ruined village over the top of the trees. But he had to focus on the moment. Even now, he could see the red glow of the humans' torches. His hand clenched into a fist as the sound of their war horns filled the air.

The sight of the human army approaching the city's edge, it filled him with…

 _Rage._

Seething, white-hot rage filled his chest cavity, his abdomen, the gaps between his ribs, _everywhere._ He would kill every human that came their way if he could manage it. He would make them pay for what they had done. True, monsters didn't like to fight, _but he was not a monster._

And so, W.D. Gaster was the first to kill a human in the Last Battle.

And ultimately, it made no difference at all.

The monsters put up a fight, but it did hardly any damage to the hordes of humans; they had no will for it. All around him, they dissolved into dust, filling the air and coating his bones. A thousand souls must have shattered around him, but he would not stop. Not while he could fight. Not while he could get revenge. Bones flew from his hands, impaling what humans he could reach. Humanity's cowardice meant that they focused on the weaker monsters, the ones they could easily kill. Only the foolhardy tried to fight him. They failed…but only for so long.

Human souls, as was well-known, are far more substantial than monster souls—and skeleton souls, for that matter. More impressively, though, they are colder, harsher. They moved like machines, methodically attacking and dissolving without regard for who or what their victims were.

He managed, for a while, to do the same. Until he recognized a face.

He didn't know this human's name. Indeed, the human probably never even saw him. But this was a face that W.D. had clearly seen at the attack on his village. And that recognition caused the rage to spill over, to consume every bit of him. A bone hit the human square in the chest. And then another, and another, and another. A strange strangled scream filled W.D.'s skull; he was startled to realize that that was his voice, and that he could not stop screaming or hurling bone after bone at the long-dead corpse.

He was an easy target.

The blow was quick enough that he didn't feel much pain; his vision immediately went black. What followed was a series of snapshots: his skull slamming into the hard ground, his body being pulled up and dragged away, walking—or maybe floating—toward a gaping hole, then a bright light before utter darkness fell. His sockets shut, and he succumbed to the darkness around him.

* * *

A low groan found its way out of his mouth. He had a moment of semi-consciousness before the pain hit him. His cheekbone ached. His joints were stiff. Everything, in some way, _hurt._ There was a loud ringing in his skull, though it was slowly fading. Strange murmurs were taking the ringing's place; with some effort, he forced his sockets open to see where he was.

A cave.

A _big_ cave, judging from all the noise. He grimaced, then forced himself to sit up before wincing and gripping his side. Broken rib. Possibly _ribs_. His fingers fluttered out a weak, "Healing, please," but he suspected it went unnoticed. He might be able to manage it himself in a while, but for now he was far too drained. He slowly laid back down on the pallet he'd been set on, staring up at the stalactites overhead. Embedded in the cave's ceiling, luminescent gems glittered down like stars. He might have thought it pretty if he wasn't in so much pain. He let out a labored breath, then turned his head to look around. Monsters were huddled everywhere, hugging each other, murmuring in others' ears. His vision was going in and out of focus, but even so, there seemed to be only…monsters. Where had his group gone?

He forced himself to sit up again, only to let out a cry of pain and fall back down, breathing hard as he grit his teeth. He could push through this pain. He had to find the other skeletons. He couldn't be the only one left. He _couldn't._

He tried to sit up again, but this time a hand pushed him down. He looked up, unable to focus; it seemed to be a monster of some sort, though all he could see was a vague, black shape. Regardless, he breathed a bit easier as they said something. Magic, then—healing magic, judging by the subsiding ache in his side. He sucked in a breath, then looked up at his healer again as they suddenly stopped speaking. Their hands—were those hands, or just overly long sleeves?—paused over his own. He frowned and began to (vainly) sign, asking what was wrong, but the action was enough of an answer.

Blood.

Human blood splattered against white bones, staining the phalanges, the metacarpals…everything.

His hands shook, and he let them fall. The healer, whoever they were, abruptly got up and left. W.D. grimaced, but sat up. He was in decent condition, now, so that meant he could search. Slowly, he got to his feet and began to look for any trace of the other skeletons. Perhaps they were outside of this cave; there were so few monsters in here that it must be only for the injured and the healers.

As he reached the edge of the cave, a fish monster grabbed his arm and tugged him back, yammering something at him. He looked at them in surprise, fingers starting to move but stopping before he formed a word. The fish-person looked at him oddly, then said something else. He merely shook his head and shrugged. The fish-person frowned, then jabbed a webbed finger toward the injured monsters. He clenched his jaw, staying put for a moment and debating feigning ignorance of what the fish wanted. Finally, though, he sighed in resignation and walked back. He may be better, but he certainly was in no shape for a fight.

He returned to his little pallet and sat down, resting his jaw on his still-bloodied hand as he looked around. The other monsters looked at him strangely; he tried to ignore them, instead focusing on the next plan of action once he found the others.

After all, they couldn't stay down here. Not forever.


	3. Lessons

Days passed.

Well, he guessed it was days, at least.

Regardless, despite being fully healed and cleaned up, he still wasn't permitted past the cave entrance. No one else had even tried to get out aside from him. _Why_? Were they in quarantine? That was his first thought; after all, the meager few monsters here _couldn't_ be all that was left. There had to be less than two hundred. And the other skeletons _had_ to have made it down, right? He couldn't be the last one.

 _Right_?

With the passing time, though, it seemed that quarantine was the less likely answer for their situation. The monsters were slowly recovering from their shock; a few had used their fire magic to light the cave and give it warmth. Meager bits of food were pooled together to feed those in the cave. Gradually, groups drew together, began talking to each other. Not that W.D. could understand a word of it. He stayed huddled by the cave entrance, waiting for the guard to lose their focus, just for a moment. Just for him to get out and find the others who had to be stuck somewhere out there. He couldn't understand them, either, but…well, he just didn't want to be _alone._

He leaned against the cave wall, idly rubbing his cheekbone. There was a faint crack there now, left over from when he had hit the ground. Probably not enough to see, but he felt it all the same. His face was just one more unfamiliar thing in this mess. He shut his sockets with a sigh. This was hopeless. If the humans hadn't—

He jumped as someone tapped his shoulder, immediately moving back. A monster was crouched beside him, holding out a bowl. They smiled and held it out to him, saying something. He looked at them tiredly, not even bothering to shrug. Another round of this, then. The monster says something, he stays silent, the monster gets mad and—

Wait.

This one wasn't mad.

They, or maybe she—the voice was light, but he had no way of telling what gender monsters were—shook her head, long, fluffy ears fluttering slightly, then frowned, as if she was trying to remember something.

"Arial?" she finally asked.

He blinked, taken aback. How did she know Arial?

"A little," he said, hesitantly. She smiled again.

"Me also." She held the bowl out to him. "Here."

His browbone furrowed, but he took the bowl and sipped from it. He nodded in thanks. She looked at him for a moment, then held up one clawed finger.

"Wait," she said, then got to her feet. He watched her go, then gulped the soup down. Skeletons could go quite a while without food—since they, well, didn't have organs—but he was still massively drained from the fight.

He had long finished by the time she returned, though he did follow her instructions and stayed put. She gave him a big smile as she held up a book, and his mouth twitched in return. She held it out as she knelt beside him, chattering excitedly before she remembered he couldn't understand her. She smiled sheepishly, then nodded down at it.

"Here." She pushed it toward him. He glanced up at her, then took the book and flipped through. He stopped at the first page, sockets widening. He understood this. Well, some of it. Arial was on the page, along with what he assumed was the monster language. He glanced up at her, then pointed at the words. She nodded.

"I learn. From…" She tapped the book. "Which are you?"

He grimaced. His language probably wasn't in here. All the same, he flipped through. He could see bits and pieces of the other major families: Serif, Console, Courier…He suddenly stopped, sucking in a breath. _No._ Impossible.

"Yes?" She leaned in.

Finally, he cracked a smile, and his hands quickly moved to say, _This! This is my language! I thought no one would know it! How did you get this book? What else does it say?_

His hands slowed as she stared at him blankly. Ah. She didn't know. He swallowed, then struggled to find the translation in Arial. "This…this, er, this mine."

"Oh!" She looked at the title on the page. "Aster?"

No, that wasn't right. How did they say his family name aloud again? "G-Gaster." He grimaced; again, it wasn't as elegant outside of its proper language. But…well, it _was_ better than hearing Wing Ding aloud. He pointed to himself. "Gaster."

"Oh! Apologize." She smiled at him as she gestured to herself. "Toriel."

"T-Tor-riel," he repeated. It sounded strange when he said it, but Toriel smiled all the same.

Someone called over to them, and she looked over and replied before turning back to him. "I, um, I go."

He nodded, then held out the book for her. To his surprise, she pushed it back with a smile.

"Yours, Gaster."

He blinked, then gave her a deep nod. He half-smiled and added with his hands, _Thank you_.

* * *

He pored over the book over the next few days, trying to at least memorize the monster alphabet and how it related to his own; the symbols were similar to Arial, but in a different order. He finally just took a stick and wrote, erased, and rewrote the Monster, Arial, and Gaster alphabets, over and over until he could do it without looking at the book. Toriel caught him working one day, and, while he couldn't understand her quite yet, it sounded like she was praising him. A day later, and she brought over a (very, very battered) grammar book.

"I think…different than yours," she said in Arial, sitting beside him. W.D. smiled wryly and nodded as he took the book. He flipped through and sighed. This book was obviously for very young children, but even so, it looked impossible to understand. Toriel lightly touched his arm.

"I will help you," she assured with a smile. She pointed to the first page and opened her mouth to speak, but was interrupted by a monster shouting urgently at her. Immediately she was on her feet and off without another word.

He looked after her, opening his mouth to call after her, but he didn't know what he could say. He sighed, then looked back down at the book.

Well.

Looked like it was time to start reading.

* * *

The time came for them to start rebuilding. W.D. had given up on finding out why they were still here, and he helped best he could with the construction. He was beginning to recognize the context of the sounds, so he could tell when he wasn't following instructions, but there was still no way for him to know _exactly_ what to do, and it was driving him mad.

More frustrating, though, was that they did things _so inefficiently._

He would not pretend that he was a master engineer or anything like that, but the few structures they had built were so haphazard. Already, one of the makeshift buildings had collapsed. There must be more practical ways of stacking rocks, he was sure.

Between studying the language and building, he sketched schematics in the dirt. Plans for a more stable structure for the survivors to live in. He heard whispers around him; they probably thought he was mad. Well, let them. He'd explain it to Toriel…whenever she came back.

That was a whole other issue. She was the only one who could almost understand him, and so the only one who could teach him. He needed her if he wanted to be able to speak, and he desperately needed to speak. But she must have been the head of some sort of committee—or, possibly, took over for the head of said committee after the fight. Whatever she was, their current state seemed to have her running ragged, and he didn't want to add to her stress.

So he stayed put in his spot by the cave's opening, sketching out his ideas for buildings and reading his grammar book over and over. At this point, he probably knew Monster better than he did Arial…well, written out, at least. He scribbled little notes around his designs, half for practice and half just in case someone decided to look.

"You learn fast."

He looked up in surprise. Toriel gave him a tired smile, then gestured down at the drawing.

"Try read these."

He rolled the stick in his hands worriedly, then sighed and leaned forward. In Monster, he wrote in unconfident letters, _I do not know the sounds._

Toriel looked at the sentence, then smiled and nodded. She held her hand out for the stick, which he gave her. She wrote out another sentence below his, then tapped each word as she said it aloud:

"Then I will teach you, my friend."


	4. Royalty

Progress was slow, both in his studies and in building their new home in the cave. Slowly, the cavern almost began looking like something livable, but with each step came more set-backs. He couldn't understand _all_ of the discussions when it came to problems, but even with his limited vocabulary he knew that morale was low.

A lot of it was due to the struggles they had with building. "That should hold" and "Look out!" were becoming the two phrases he knew best. In a week, three structures went up; two came down. One monster didn't get out of the way in time.

On the brighter side, he could speak the language now, sort of. He'd managed to work out a system, assigning a sound to each of his hand signs. It often took him a few tries to sound out what he wanted to say—the sounds were still strange and never seemed to come out of his mouth quite right—but it got the job done. And he suspected it took some of the pressure off Toriel when it came to teaching him. Oh, she did her best to stay cheerful during the lessons, and he was very grateful for that, but it did barely anything to hide her stress.

"What is wrong?" he finally asked the day after the collapse. He expected her to be affected—after all, it was always her who was there to help any monster in need—but she looked even more tired than usual. She met his sockets, then gave a light, mirthless laugh.

"You should stop using your hands with simple phrases, my friend," she said. He gave her a wry smile in return.

"Please, it…er, it helps. But you, er, you…" His browbone furrowed, and he slowly signed the word. "…ch…chah, chay… _change_ the subject."

Toriel sighed. "You are very perceptive." She gestured to the rubble still at one end of the cavern. "But I am certain you have noticed we are not rebuilding well."

He grimaced, but nodded. Toriel buried her face in her hands.

"We cannot survive if we are unable to even house ourselves. Asgore and I have been trying _so hard_ , but…" She shook her head.

He looked at her sympathetically, hesitantly reaching out to pat her arm. Asgore. He'd heard the sounds from the other monsters here and there, but he hadn't even considered it would be a name. "Who…er, who is Asgore?"

Toriel lifted her head and took a deep breath. "My husband," she explained after a moment. "He has been discussing strategy with one of our top warriors for days, and he is no closer to figuring out this… _situation_ than I am." She shook her head. "I am half-afraid he will dissolve from the stress. He has not been king for very long and…"

" _King_?"

Toriel looked up. "Well, yes."

He gaped at her. True, skeletons didn't have monarchies, but he wasn't an _idiot_. Kings were important. And if Toriel was married to the king… "Then…so…so you-you are…are the…"

She eked out a half-smile. "The Queen, yes."

He stared at her silently, then covered his face in embarrassment. "Oh, god." He didn't need to sign that phrase. "I…I waste…so much of time!"

"Oh, no! No, no, not at all, my friend!" Toriel assured. Now she was the one patting his arm. "You are learning quite fast, especially your writing. And, if you do choose to make a home with our people, then I would like you to be as comfortable as possible." She smiled a bit and added, in a whisper, "And, between us, I have always wanted to be a teacher."

He looked at her curiously for a moment, then smiled. She returned it, then pressed a claw to her mouth, brow furrowed in thought.

"Show me what you have been working on," she said suddenly.

He blinked. His sketches? That had to be what she meant. "Er…yes, okay." He got to his feet and brought her over to the sketches. They had grown substantially since he'd first begun drawing in the dirt, with so many notes written around the diagrams they were nearly illegible. Around them was a circle of rocks, to keep them from being swept away by a careless monster. Toriel crouched down to examine them, and his hands fluttered awkwardly before he managed to speak.

"Er…it…it is a p-l-plan. For booeel…for _building_. Er, efficient. More safe." He grimaced at his garbled explanation, then stood silently as Toriel continued looking over them. Finally, she looked up with a smile.

"My friend, I think you will need some paper."

* * *

It turned out that there were more "rooms," so to speak, in the cavern, though still very, very few monsters. Toriel guided him through the path, weaving easily between fallen rocks and stalagmites. She occasionally stopped to speak to…well, her _subjects_ , but was always quick in returning to his side. Even so, it was still strange to think of her as a _Queen_. He still wasn't quite sure what monarchies were like, but he never expected someone so kind to be royalty.

She stopped at the base of a very steep hill, glancing back at him worriedly. "I am sorry, but this is the only way to where we must go."

He half-smiled. "I am…fr…I am not fr…er, fray…" He shut his sockets with a quick breath, figuring out what he wanted to say. "I am not fr- _frail_ as I appear." He smiled again. "I can walk."

Toriel returned the smile. "Follow me, then."

They made their way up, until they were on level ground. Toriel guided him to an almost closet-like niche. His sockets widened as he saw the books, papers, ink, and even jars of honey and preserves hidden inside. "How…?"

She sighed. "We had known an attack like this was coming, so Asgore and I planned for the move to Mt. Ebott when the time came. We tried to move whatever valuables and necessities we could manage down here, to create a hiding place." She shook her head. "But the food will only last for so long. We should have started earlier. I should not have brought so many books…"

"Do not be," he quickly said. Given her strange expression, he guessed that wasn't his best translation. He gave her a smile. "I…I could not have le…lea…leayrned without your book."

Toriel glanced up at him. " _Learned_ , my friend," she corrected gently, mouth barely turned up. "The 'a' is silent." She looked back to the stack of books in the corner. "And I suppose…it will be useful once we are settled. Children still need to learn." She stepped inside the niche, pulling out a few sheets of paper and a couple pencils. "And they need somewhere to live." She handed him the supplies. "I think this will be far nicer to work with than sticks and dirt."

He looked down at supplies in his hand, then sent Toriel a wide grin. This would be _much_ better. He could write his notes more legibly, detail the supports for the structures, show the angl—He looked up Toriel touched his arm as she looked down the passage. She gave his arm a small tug as she said, "Come."

His browridge furrowed, but he followed after her. He clutched the papers to his chest protectively as he heard two voices in what sounded like a heated debate. Was this something to fear? He looked up at Toriel. Judging by the smile on her face, not something to fear, but…still. He had the feeling he was going somewhere he didn't belong.

They reached a wide room of the cavern, where a tortoise-like monster seemed to be lecturing another monster who looked like a bigger, blonder Toriel. The tortoise-monster spoke in a quick, urgent manner, making translation nearly impossible. He was able to pick out a few words, such as "stay here," "foolish," "safe," and some inconsequential pronouns, but other than that it was a mystery. The other monster crossed his arms; his face looked focused, but his eyes were somewhere else. Toriel cleared her throat, and this monster looked up. The worry melted from his face as he walked up to her.

"Tori!" In two quick steps, he was in front of her and hugging her tightly, burying his face in her white fur. "Oh, you have _no idea_ how happy I am to see you, dear."

Toriel smiled and rubbed his back. "I have an idea," she replied, then murmured something that almost sounded like "Fluffybuns." But surely Toriel would never call someone a name so horrible. She stepped back after giving her husband an extra tight squeeze, then cleared her throat and stepped back. "I would like to introduce you to Gaster. From the skeleton village."

He almost corrected her; after all, Gaster was his family name. But…well, it _did_ sound much better than Wing Ding did out loud, and…it wasn't like there would be any confusion.

Really, going by his last name might be the only chance the Gasters had to keep from being forgotten.

He smiled and dipped his head respectfully. "I am, er…" Oh, god, he couldn't sign with his arms full of paper. What were the sounds? He carefully pulled one arm free and did little half-motions. "I am…pl-pleased to m-meet you." There. He got it.

Asgore smiled at him, reaching a large paw out to shake. Gaster prepared to lose his arm, but the shake was surprisingly delicate. "Howdy, Gaster. I'm Asgore." He motioned to the tortoise. "And this is Gerson, the Hammer of Justice, as the people call him." He chuckled, but Gerson merely looked at him impatiently. He said something, but again it was that quick voice that Gaster couldn't decipher, so he gave him an awkward smile in reply.

"The skeleton village, though. That's a good ways away; how did you find Mt. Ebott?" Asgore asked, stroking the white fur on his chin thoughtfully.

"Gorey, I do not think this is the time…" Toriel started to say, but Gaster shook his head.

"It is fine," he said. He let out a breath, setting his mouth in a straight line. "The humans…we had to…"

Asgore sighed before he could say anything else. "I understand." He gave Gaster a sympathetic look before patting his thin shoulder. "But…well, I promise that you and the other skeletons will be more than welcomed into our community."

Gaster stayed silent, but his mouth twitched and his throat tightened. _What others_? He looked away as Asgore drew back, then curiously looked back at his shoulder as a smaller paw rested on it.

"Before you resume your strategizing," Toriel said, making Asgore turn back from Gerson, "you should know that Gaster has been designing ways to improve our structures. Perhaps you could take a look when you are free?"

Asgore smiled. "Of course." He stepped forward, gently taking her shoulders and pulling her close to nuzzle snouts. "I'll see you soon, honey."

Toriel gave him a wide smile and a kiss on the cheek, then returned to Gaster's side. "Come, my friend. We will get to work at once."

He gave Asgore one last deep nod, then followed Toriel out. As they picked their way back down to the other monsters, he looked at Toriel with concern.

"I…I am not…er, not, erm…er…" He still couldn't sign, not if he didn't want the papers flying as they walked. "Why you… _did_ you…" He let out an annoyed grunt. What were the _words_?

Before he could get too frustrated, Toriel paused. "Why did I mention your work to Asgore?" she finished, then turned back to him. "Because, my friend, you are the only one thinking of improvements rather than resigning ourselves to our current situation." She gave him a smile. "And that is exactly what we need."

* * *

With all the work being done to make up for the collapse earlier in the week, Gaster wasn't able to work on his plans until the other monsters decided to call it a day. Again, progress was slow, but this kind of planning was much more enjoyable than stacking rocks and learning sounds. So he sat up long into the night (well, he assumed it was night), sitting as close as he could manage to the dying communal fire for light and drawing diagrams until his eyes couldn't focus.

He'd gotten about three full blueprints done and was working on his fourth when something tapped his shoulder. He jumped up nearly a foot, just barely keeping a hold of his paper. He looked up, and his browbone rose as Asgore crouched beside him.

"I didn't mean to scare you," he whispered. Gaster shook his head.

"It is fine," he said slowly. "Er…why…why you here?"

Asgore sighed. "We're stuck on our next plan of action. Food's running low and…" He gestured to the ramshackle structures. "We can't survive like this. So I thought I'd see what you came up with."

Gaster frowned. "Now?"

Asgore shrugged. "I had a feeling you'd be awake." He lightly touched the completed blueprints. "May I?"

"Er, yes." Gaster set down his current paper, turning fully toward Asgore. "It…er, I am not…" He huffed. "No ex…experi-ence. But it, er…it is close to my home. I-I mean…" His hands shook a bit as he tried to sign the words he wanted to say. He'd never had to say this much to anyone aside from Toriel. "Er, it is…skeleton-style."

Asgore looked up at him. "The way things were built in your village?"

"Yes! But also…like a skeleton…" He shook his head and covered his face in embarrassment. He sounded like an idiot. "I am sorry. Bad ex-explay-explanation."

"No, no. Take your time, Gaster," Asgore said kindly.

Gaster let out a breath, then held up his hand and pointed to it. "You see…erm, you see how the hand?"

Asgore blinked. Gaster huffed.

"It…it fit! Together!" He pointed to his carpal bones, then down to his radius and ulna. He then jabbed his finger at his wrist joint, where they all met. "It fit! Like this!"

Asgore frowned a bit, then snapped. "Oh! It all locks together?"

"Yes!" Gaster smiled, relieved that the message finally got through. Asgore nodded, then looked over the blueprints again.

"There's a lot of materials we don't have in here, though," he murmured thoughtfully.

Gaster's expression fell. He hadn't thought of that. He sighed, then crumpled his current paper and tossed it into the fire. Asgore's eyes widened.

"Why did you do that?"

Gaster frowned. "Useless. No ma-materials."

"I didn't say that it was useless," Asgore said with a smile. He looked over to the entrance to the cavern. The guard was still there. "But I think it may be time for an expedition."

Gaster stared at the opening, then turned back to Asgore, hands moving as he quickly whispered, "Can't…we can't…no one can go. Not there. Not allowed!"

Asgore grinned and gave Gaster a wink. "Good thing I'm the king, then, isn't it?"


	5. Expedition

"This is _suicide!_ "

Those, surprisingly enough, were the first words from Gerson that Gaster understood. The tortoise had pulled himself to his full height—though he was still dwarfed by the other three monsters in the cavern—and narrowed his eyes at Asgore.

"I'm gonna talk _niiice_ and _slooow_ because _obviously_ royalty doesn't account for brains," he said. "Now, you may be a Boss Monster, King Fluffybuns, but I'm a good deal older than you. I've _seen_ what happens when monsters start letting their guards down."

"But the _Barrier_ , Gerson…"

"I don't give a single _damn_ about that Barrier! Humans do _two things_ : fight and die! If you think a dinky little magic wall— _even one they built_ —is gonna keep them from killing us, then you're a damn fool, Asgore Dreemurr."

"We're not settling out there," Asgore argued. "It's reconnaissance."

Gaster, best he could, tried to melt into the cave wall he was leaning against, just in case Gerson was about to blame him for the king's idea. It _was_ a little…impulsive. But, well, the situation was dire.

Really, though, he didn't even know why he was here. He could barely speak, he had no recollection of getting to the cavern, and _he wasn't even a monster._ But Asgore had insisted, and…it turned out the king was really a hard person to say no to.

So here he was, standing by the wall beside Toriel, watching Asgore and Gerson battle out whether Asgore would go out or not. Gerson had begun using his quick voice again, so Gaster was lost. Toriel shook her head.

"We may be here for a while," she said quietly. Gaster sighed.

"My fault," he said. "I…er, my…the paper…"

Toriel shook her head. "Definitely not, my friend. He's wanted to go for weeks; you just gave him reason to."

Gaster looked at her curiously, then back at Asgore. So he hadn't been the only one itching to explore, though he doubted Asgore's reasons lined up with his. Huh.

"Well, you sure as hell aren't going alone," Gerson said, once again speaking slowly to mock Asgore. "But I'm not going with you. Your wife here's too smart for that, too. So who would be crazy enough to go with you?"

"I will."

All eyes turned to Gaster as he spoke the clearest words he had in weeks. Reactions varied; Toriel was shocked, Gerson distrustful, and Asgore was positively beaming. His hands fluttered awkwardly at all the attention.

"I…I will go with the king," he repeated, though the added words made him falter.

Gerson scoffed and muttered something, but given the way that both Asgore and Toriel said " _Gerson!_ " made him think it wasn't anything flattering. Perhaps it was better he couldn't understand that.

Toriel turned back to Gaster, taking his arm.

"My friend, you do not need to go. We could find other volunteers, I'm sure. There's still the guards and…"

Gaster shook his head as he pulled his arm away. "I will go." He gave her a small smile. "Not as frail as I look, remember?"

Toriel didn't look even the slightest bit relieved, and Gerson threw up his hands.

"Fine! Trust a _skeleton_ with the king's life! That's a _great_ plan, Fluffybuns!"

Gaster frowned. "I am not…not a danger," he retorted.

"The humans said the same thing." Gerson spoke exaggeratedly slow; even Gaster could tell he was being mocked. He set his jaw, and stared silently at Gerson, though his hands signed a multitude of not-quite-polite epithets at him.

Asgore stood between them. " _Please._ We do not need any more fighting," Asgore pleaded. Gerson and Gaster glared at each other, but both stayed quiet. The king let out a sigh of relief.

"There. It's settled. Gaster and I will go out, and we'll come back with a report of what the rest of the Underground is like." He smiled and clapped Gaster's bony shoulder. "And then come back to get our new home properly up and running."

* * *

" _Read this_ while you are out there."

"Tori, really…"

"I am serious. _Read this._ I will not have you dissolving after all we have been through just because you made tea out of something you were not supposed to."

Asgore sighed, but relented. Toriel slipped a large book titled _The Guide to Subterranean Plants_ in Asgore's bag. She let out a breath, then met her husband's eyes.

"Promise me you will be careful," she murmured. Asgore smiled and wrapped his paws around hers.

"I will be amazingly careful, my dear," he assured warmly, kissing her snout. Toriel smiled before nuzzling it against his.

Gaster adjusted his hold on his own bag and fought rolling his eyes—well, as much as he was able to withouteyes. Certainly he liked Toriel, and Asgore was growing on him. But _good god,_ were they insufferable together!

They continued nuzzling, and Gaster finally had to unnecessarily clear his throat to get the king's attention.

"Oh!" Asgore smiled sheepishly, then gave Toriel one last kiss. "Like I said, we'll be back in no time, my sugar-sweet." He finally pulled himself away from his queen, then smiled at Gaster. "Ready to go?"

Gaster half-smiled at the king's enthusiasm and nodded. They both began making their way down to the hill back to the other monsters. Toriel waved after them.

"Be safe! Both of you!" she called after them. Gaster glanced back at her with a small smile, which died as he turned around.

Oh.

He'd be alone with Asgore. He'd have to talk to him.

But he hadn't spoken properly to anyone but Toriel!

Gaster stopped dead in his tracks, sockets wide. Asgore _did_ speak rather slowly, but what if he couldn't understand him? Would Asgore lose his patience after too many "Beg pardons"? Would _Gaster_ lose patience? Friendly as he was, Asgore was clearly the stronger of the two, so if there was any sort of confrontation…

"Gaster?"

Gaster blinked as Asgore said his name. The king had stopped and was looking at him curiously, but not unkindly. He put on a smile.

"I am coming. Got…er…too, too many thoughts."

Asgore's expression shifted to one of concern. "If you've changed your mind about coming, you certainly don't have to."

"No! No, not those, er, not like that," Gaster assured, taking a few quick steps to catch up to Asgore. "I want to go."

Asgore grinned at him. "So you've been bitten by the exploring bug, too, then."

Gaster blinked. "I…do not think anything has, er, bite me." He pushed up his sleeve to examine his bony arm. "I would have, er…well, it would have, er, hurt, I think." He jumped at Asgore's loud snort, as did a few of the monsters around them. Asgore covered his mouth and shook his head, still smiling.

"I don't mean a real bite," he explained with another giggle. "It's an expression."

Gaster set his jaw tightly. Was Asgore making fun of him? He hung back a moment as Asgore went to speak to the cave guard, looking at the king warily. He debated backing out, but…well, there was still the chance that the other skeletons were out there. And, really, he was _desperate_ to see what was on the other side of the cave's opening. He sucked in a deep breath as Asgore turned and beckoned him to follow him out of the cave, still grinning.

Even so, this might be a longer trip than he thought.

* * *

Initially, the area past the opening was just like the cave, which honestly left Gaster disappointed. He'd expected…well, he hadn't known what, but something more exciting. Especially with _how much_ they had been discouraged from even looking outside the opening.

He sighed as they reached the end of the tunnel, staring balefully at the rock wall in front of them. Well. There was their expedition. He looked at it for a moment longer, then turned and started to walk back.

"Gaster!"

He turned as Asgore, looking baffled, called after him. He shrugged.

"This…er, this is…this end."

Asgore grinned. "Not quite. Watch." He wrapped his arms around one of the huge rocks. With a grunt, he pulled it back. Gaster's sockets widened as a blast of chilly air swept into the room. There was…more? He took a few steps forward as Asgore leaned against the rock to catch his breath.

"See? We've still got a ways to go until we reach the end," the king said with a smile. He stood up straight before nodded to the opening. "Come on, Gaster. Time for some real exploring."

Gaster followed after, squinting at the bright white light they were walking into. He blinked a few times, then looked up as he felt something settle on the top of his skull. He looked up, a smile slowly spreading across his skull as he realized what it was. His hands excitedly jerked out a word.

 _Snow!_

It really was snowing on them! But there was no sky; they were still underground. How was this even happening? He laughed as he took a few crunching steps forward.

"A-amazing!" he finally stammered out to Asgore.

"You don't remember this from when we came through?" the king asked with a smile. Gaster shook his head.

"I, er…I was…" He didn't know the word for this. "Er, like sleep but not…not good." He huffed at his terrible explanation, then mimed hitting his head as he shut his sockets.

Asgore watched him curiously, then nodded. "Ah, right! I'm sorry, I didn't know."

Gaster let out a little breath, a little irritation breaking up his excitement. He was _hoping_ Asgore would give him the word, the way Toriel did. But…well, at least he wasn't laughing this time. He shook his head and waved a hand.

"It is, er…unin…unin-port-ant." That didn't seem right, but Asgore wasn't correcting him, so he supposed it was. Unless Asgore was just being polite. Perhaps he'd completely butchered the whole sentence? What if he'd been butchering sentences this whole time, and Asgore was letting him fail so he could laugh more? Gaster's hands fluttered awkwardly before he finally added, "Let us…er, let us go more."

He abruptly turned and started walking, trying, vainly, to outrun his embarrassment. This was awful. He shouldn't have agreed with this, not with how little he could communicate. Asgore probably thought he was some kind of idiot. Maybe he was. After all, it must have been about two month since the battle, and he could still barely get a full sentence out. Certainly he'd always had a hard time with languages, but being immersed like this he shou—

His thoughts were cut off as something cold and soft hit the back of his skull.

He quickly turned, hands raised, only to lower them as he saw Asgore, pack dropped to the side, shaping another snowball. He looked up and grinned at Gaster.

"Obviously we need to see if the snow here is the same as the snow above ground," he said with mock seriousness, then launched another snowball at Gaster. The skeleton narrowly dodged it, but Asgore was already making another. "You know, you should check, too!"

Gaster hesitated. Was Asgore serious? They were on an expedition; he'd already embarrassed himself enough trying to speak. Surely acting like a child would only make things worse. He looked up at Asgore once more. Asgore tossed is ball up and deftly caught it, eyebrows raised at Gaster. Finally, the skeleton let out a breath as he let his pack drop from his shoulder, and he swiftly scooped up some snow with a smile.

After all, snowball fights didn't need any words.

* * *

Eventually, it was time for them to do their actual reconnaissance. The two called a truce and actually examined the snowy area. While the snow had been the first thing Gaster noticed, the oddest thing were the large, fully-grown trees throughout, creating a thick forest around them. So it looked like wood for the buildings wouldn't be an issue…and, perhaps, for some bridges; while two monsters could get across the ice bridges easily enough, it was clear that they wouldn't last for long if the monsters decided to expand out.

Still, it was growing later, and there was no way they could spend the night in the cold. Well, not Asgore, at least; even through his thick fur, the king was beginning to shiver. Gaster was feeling fairly good, but he expected that was because he had no skin. So they kept moving.

The snow lasted a while yet, and Asgore picked up a few branches, just in case he'd need to warm up. Luckily, though, they finally reached a fairly solid ice bridge that ended in a much-less snowy cave. This one was darker and more damp, and they both stopped at the sound of running water. Asgore frowned, then handed the branches to Gaster; the skeleton nearly toppled over from the weight of them.

A small fire lit itself in Asgore's hand, and he held it up to examine the area around them. "Gaster, look! Waterfalls!"

Gaster peeked around the branches to look. Indeed, small waterfalls poured down into a little river on one side of the path. He smiled and opened his mouth to reply, but he had no way to sign out his words. So he simply nodded, remaining silent. Even after the snowball fight had dissolved much of his tension with Asgore, he didn't want to look foolish.

They continued on; Asgore took the branches back as they went further. What seemed to be crystals in the cave walls illuminated everything, casting a dim blue glow just bright enough for them to see by. Gaster's skull was threatening to swivel off his spine from how much he was looking around. How did the crystals light themselves if there was nothing to reflect? Were they producing their own light? He stopped at one of them and tried to pull it out, but it was firmly lodged in the cave wall. He'd have to look for a fallen one.

As they walked through the cavern, Asgore chattered away. Gaster _knew_ the king was trying to be friendly, but really, it was a little irritating; after all, he could only understand every fifth word or so. Even worse, Asgore would ask _questions_ , and Gaster would have no choice but to stammer out a garbled reply that likely made no sense.

They waded across a little waterway. Then a second. Then a third. After the fourth, there was a mutual agreement that they would stop in the next part of the cavern. Exploring in wet clothes was in no one's best interest, and it was probably time for them to call it a night anyway.

Gaster was the one to lead the way into the next room, and he stopped dead in his tracks. This room was…

It was _beautiful._

It was darker than the other rooms, and mercifully dry; overhead, a scattering of crystals sparkled like stars in the night sky. Throughout the room, there were tall blue flowers that seemed to be _thrumming_ , emitting a low, peaceful hum. This was precisely the kind of place Gaster would have _loved_ to have found above ground, where he could have hidden away for some time alone.

Asgore stepped in behind him, and judging from his gasp, he was also struck by the beauty of this little cavern. Gaster's hands moved to share what he thought, but he stopped. Once again, irritation ruined his enthusiasm.

"I…I am sorry…I w-wi-wish…I…not sleep….too long…" He finished his nonsensical statement with a sharp, frustrated noise. "I w-i-sh I see…no, I…." Another grunt as he threw his hands down. It was _useless!_

Asgore looked over at his companion in surprise, and he set down his branches. "Hey, it's all right. Take your time and try again," he said gently.

Gaster gritted his teeth, furious at himself and ashamed at the obvious pity Asgore was giving him. His fingers flexed before he finally signed out a very big sentence.

 _I CAN'T!_

Asgore looked surprised at the movement, but the floodgates were opened. Gaster was signing incessantly, words spilling out of him so fast that even his family wouldn't have been able to understand him.

 _I can communicate! I_ know _words! I'm not an idiot! I could go on for hours in conversation, I can talk about complex thoughts and emotions. I'm in awe of this room! I'm devastated to be alone! I can understand all of these concepts easily. I shouldn't have to be a pet project!_

He looked up at Asgore, shoulders sagging as he caught the king's blank look. _But you couldn't understand a word I just signed. So I have to keep sounding like a_ child. He let his hands drop, and he shook his head before slinking off to a corner of the cave.

"Gaster, wait!" In a few short bounds, Asgore was at his side. "Look, I-I'm not as good as Tori when it comes to teaching, but…but I can tell you're frustrated…"

 _Understatement of the year_ , Gaster's hands said as he huffed.

"And I know it's hard. I know I couldn't learn this language; it's not very organized…but you _can_ do this, Gaster!"

Gaster didn't reply. His hands tightened into hard fists as he grit his teeth again.

"If you just…if you stay focused, then I know you can…"

"I canNOT!"

The words exploded out of Gaster. Then, to his surprise, they exploded back at him, over and over. He and Asgore both looked around in surprise. Finally, Asgore walked over to one of the blue flowers. From the center of its petals, Gaster's strained voice shouted over and over. Quite frankly, it was eerie.

Gaster took a few deep breaths as his voice echoed in the cave, each repetition adding to his doubts. He couldn't do this. He couldn't learn this awful language, he couldn't listen to his hideous voice shouting in a multitude. He couldn't _help_ anyone. He quickly shook his head and ran out to the other opening, ignoring Asgore calling him back.

He stopped as he reached the end of the land. The water was too deep for him to rush out into in his state. So he dropped down into the dirt and shut his sockets, bringing his hands up over his head in an attempt to get the sound of the flowers out of his head.

Maybe he should have just been left behind. It'd be preferable to this hell; he wouldn't have to talk.

He didn't move as he heard the quiet footsteps behind him, nor as he felt Asgore sit down beside him. Remarkably, the king stayed silent. The flowers from the room behind them slowly muted themselves, leaving only the little lapping of the water against the dirt.

Finally, he heard Asgore let out a small breath.

"I'm sorry," he finally said.

Gaster grimaced, hands moving away from his skull to sign, _I hate this. I want to go home._ It was petulant and childish, but Asgore couldn't understand him, so what did it matter?

Another silence stretched between them. Asgore sucked in a breath. "I…have some trouble, too. With words. Not in the same way, obviously, but…"

Gaster glanced up as Asgore trailed off. The king put on a wry smile and shook his head.

"I didn't want to be king. I'm not very good at…speeches or making everything okay. I can barely even take care of the monsters that made it down here. I can't even keep them _happy._ " He rubbed his muzzle. "So if I'm having a hard time, I can't imagine what you're going through." He looked up at Gaster. "But even with everything that's happened to us, and being somewhere new and strange, you've come up with a way for us to make our situation work! You're actually thinking and learning and that's really something!"

Gaster looked up at him, head raising ever so slightly. "What…something?"

"I mean that it's great," Asgore clarified with a smile. A kind one, without a trace of a laugh. Gaster swallowed.

"You…do not th-think I am…" He slowly signed out the word, grimacing as he did. "…st-stup-stupid?"

Asgore blinked, then laughed. A surprised one.

"Stupid? My god, Gaster, you've come up with a blueprint for our whole society! You're definitely not stupid." He smiled and shook his head before looking up at the skeleton. "Well…I think the next room's quieted down. We can head back and make camp there. Would you like me to make you a cup of tea?"

Gaster hesitated, fingers twitching.

"We don't have to talk," Asgore added gently.

Gaster looked up at him, then let out a breath as he shook his head. "No. We can. I-I need to learn." A small smile finally broke through. "Thank you, Asgore. For…for talking."

Asgore chuckled. "You're the first person to thank me for that." He got to his feet. "Now, Tori will kill me, but I found some interesting plants in the snow area that I think might make _excellent_ tea…"


	6. Discoveries

The night passed without much incident. They chatted, Gaster's quick, disjointed speech contrasting with Asgore's slow and easy tone. Gaster was dumbfounded (well, more than usual) at all that being a king entailed. Asgore was appalled at the monsters' distrust of skeletons; his goal was to have a kingdom that welcomed all.

"Before my coronation, I wanted to welcome all species into our kingdom," he explained as Gaster listened curiously. The king gave a bitter laugh as he played with a seed he'd found. "Even humans, though obviously that's…not in the plan now." He shook his head. "I was foolish. I—it's strange. I never really _understood_ that I'd be king. I mean, I knew that I'd get the crown, but…I don't know. I didn't acknowledge it until it really happened." He sighed as he pushed the seed into the ground, then gave a little chuckle. "I really wanted to be a gardener. Something where I could use my hands and _make_ things instead of passing laws and retreating into a mountain." He looked up at Gaster. "What did you want to do? Back on the surface?"

Gaster blinked. He looked down at his hands, thinking, then shook his head. "I do not know. It was…strange, in my family. We…well, we did not co-communicate well, as I am sure you can imagine. So…we mainly fo-focused on pr-proveeding…" He grimaced; that didn't sound right. "…for ourselves." He thought for another moment, then let out a small, rough laugh. "One of my…er, sister, I think is the word? My sister, she want to be a…she, er, she want to…" He motioned the word, thinking back to the grammar book. "Dance! That is the word! And we all ask—" He started to motion the question, but the curious look on Asgore's face reminded him that he couldn't understand. "Er, we all ask, 'Freesia, how will you be see? You do not speak Arial!' And…and she say…" He chuckled before signing and speaking, "She say, 'I will not need to! My hands _and_ my feet dance, so I will be best!'"

Gaster laughed again, but the sound became strangled as he felt his throat constrict. He swallowed hard as he felt the bottom of his sockets grow wet. He quickly covered his mouth and shut his eyes. "I-I am sorry."

Asgore remained silent, but Gaster was aware of a large paw suddenly squeezing his shoulder. The motion was sympathetic; well, of course it was.

They'd all lost so much in that last battle.

The silence stretched, and Gaster took a few deep breaths to steady himself. Asgore drew his hand back.

"If…if you need to talk…"

Gaster shook his head sharply, sockets shutting tighter. He couldn't. Not now. He wasn't ready. Maybe he'd never be ready.

Finally, he pulled his hand away and let out one last breath.

"I…I think I will sleep," he finally said, voice wavering slightly. He looked up at Asgore, who nodded.

"We probably need it," he said, then laid down. He peeked over his shoulder. "Good night, Gaster."

"Good night."

Gaster laid back on the ground, staring up at the crystals overhead. He sighed as he shut his eyes.

Maybe one day he could think about his family without breaking down.

* * *

It took a while, but Gaster was eventually able to drift into a troubled sleep. All too soon, though, he was jolted awake as a loud cry echoed through the little cavern. Before his sockets were fully open, Gaster was sitting up, holding out his hands for an attack.

"What is wrong?" he asked quickly, looking around the cave. He saw Asgore, eyes wide, point silently down to a little sprout. Gaster frowned, hands lowering.

"A…plant?"

"It's where I planted the seed!" Asgore said, voice hushed in shock. Now fully conscious, Gaster noticed the book Toriel had given the king was open in his lap. "It shouldn't have sprouted that fast, especially not in these sort of conditions."

Gaster blinked a couple times, then furrowed his browbone as he leaned down to look at the little blue stalk. "It, er…it must be…it must be how it is."

"But it's _not!_ At least, not the way a typical flower in its family would grow," Asgore said, frantically flipping through the book. "Even if we're underground, that shouldn't change its basic growth pattern."

Gaster glanced up at Asgore, then back at the tiny little sprout. He lightly touched the stalk, then idly spun his fingers around it as Asgore kept flipping pages.

 _"Ah!_ "

Asgore looked up in alarm as Gaster jumped back. The sprout had grown another inch. Now they both looked down at it in alarm before meeting each others' gaze, eye to socket.

"Did you do that?" Asgore asked, voice quiet again.

"I…I do not know. Maybe?" Gaster's hands fluttered for a moment, then he carefully reached out his hand and repeated the motion.

" _Ah!_ "

This time they both cried out in surprise as the sprout grew another inch.

"How is this even _possible_?" Asgore asked, setting the book aside and practically laying in the dirt to get a better look at the sprout.

Gaster, meanwhile, flexed his hand a few times. Oddly enough, he felt just a little drained from that. Like he'd used a bit of… His sockets widened, and he quickly pat Asgore's shoulder. "You, you…you try!" he said as quickly as he could manage. "Try to…er, to, er…" He motioned to the plant. "Like me!"

Asgore looked up at him, then pushed himself up to his knees. He glanced at Gaster, who nodded quickly, then reached out his hand and pulled upward. He gasped as the sprout shot up a foot. Gaster's sockets widened still more, and a grin spread across his skull. Of _course!_

"Magic!" he blurted out. That was the only answer. But how could they do that here? Was it the species of flower? Or would other plants do the same? Why _couldn't_ other plants do the same?

He was broken out of his reverie as Asgore spoke. "You think _magic_ did this?"

Gaster looked up and nodded eagerly. "Not…I do not know _how_ , but it must be!" There must be some explanation. A little hand wave would have done nothing on the surface. Why was it strong down here?

He needed to find out.

He _would_ find out. Somehow.

He looked up in surprise as a heavy paw rested on his shoulder. Asgore, still looking at the plant, was positively beaming.

"Gaster, my friend," he said after a moment. "I think we might be able to survive down here."

* * *

The rest of the water area was, really, far too wet and not all that exciting. There _was_ a wall that Gaster swore he could hear voices from…but there was no opening anywhere around it. No doubt it was just a trick of his imagination; it would be the only explanation why it sounded like the voices were speaking Serif.

Interestingly, they _did_ find some other monsters who seemed to be fairly established here. They were fairly low-level and generally not able to really communicate. However, there was _one_ group that seemed to have formed a genuine village. Gaster and Asgore were thrilled, of course. If they could create a community, then there was hope for their own group of monsters beneath this mountain. However, there was no way to find out how this community thrived. Every question they asked was just met with "hOI! im temmie!"

They left the village.

Really, the only place of viable interest was at the very furthest end of this water cavern. One particularly large waterfall emptied out to a shallow, but wide pool, and apparently came directly from the surface, washing things from above ground down below. Right now, it was mainly rubble from the war, but they sifted through it all to find a few things that might be helpful back at their base camp: tools, bits of metal and driftwood, things of that nature.

And a book.

Gaster had found it just as they were leaving; the cover, soaked as it was, still looked interesting He picked out the most legible word on it.

P-H-Y-S-I-C-S.

He couldn't even imagine how that was pronounced.

All the same, he tucked the book into his bag. Might be an interesting read some day.

* * *

Blinding hot heat was what greeted them next. Even without eyes, Gaster squinted as they exited the water area. Once he adjusted to the bright red light, he stared with wide sockets at the sight in front of them.

He'd known that there had been a volcano near the village. He'd heard stories of the one time it erupted, the geyser of fire the village had seen through thick smoke.

 _This_ , though. He could have never dreamed of _this._

He took several steps forward and stared down over the precipice at the roiling, churning sea of magma. It stretched out as far as he could see, never stopping its motion. He tilted his head forward slightly, fully aware that one wrong step would have him swallowed up by the molten rock below.

He'd never seen such raw power in his life.

Something strange thrummed in him as he stared out at it. A strange, almost primal desire crept up in the back of his mind in the face of this great force that almost seemed to challenge his frailty in the face of its immense potential for destruction.

He wanted to _conquer_ it. To prove that _he_ could tame this unstoppable force.

He blinked, feeling almost as if he'd woken from a dream. Where had _that_ come from? It wasn't the least bit rational. After all, who was he to control nature? He took a few steps back, then glanced back at the magma.

Then again…he _had_ made that flower grow.

"I think this is as far as we'll get," Asgore said, pulling Gaster's attention back to him. The king looked out at the magma, though he didn't look quite as awestruck as Gaster had felt. "The barrier's not far, and we barely made it across from there the first time. It's too dangerous for us to get to it." He smiled wryly. "And anyway, it's not like there's anything we could do about it."

Gaster glanced once more at the magma, then back at Asgore. "Er…I am sorry, but what is 'the Barrier'?" he asked tentatively. "I…I have heard about it, er, o-often, but I…I do not understand."

Asgore stared at Gaster. "You don't _know_?"

Gaster grimaced. "I was…er, I was…" He mimed knocking on his skull again. Asgore sighed and nodded.

"Right, I forgot." He looked away, then gave a grim smile. "Well, I guess no one really wants to talk about it. Long story short, the humans put up a barrier to keep us here for good."

 _What?!_

Gaster was so shocked he merely signed the exclamation. _For good_? Did that mean forever? But why? What had they even done to deserve this?

Clearly Asgore understood what Gaster was feeling. "I know. I don't know what would drive them to such needless cruelty, but…" He sighed. "That's the way things are. We can't get out." He laughed bitterly. "Well, not unless you have seven human souls on hand."

"You try?" Gaster asked desperately. Asgore grimaced and shook his head. Gaster's hands moved in a flurry, not quite forming words. Eventually, he was able to find the only monster word he could think of. " _Why_?"

"Because we needed to save the monsters who were left," Asgore said, very consciously not looking at Gaster. "We had already planned to move here if things got too bad. But…we didn't expect that it'd be so… _permanent._ " His broad shoulder sagged, and the king was silent for a long moment before he looked up, forcing hope onto his face as he looked at Gaster. "But…we need to focus on the _positives._ I mean, look at all we've managed so far! Look at what _you've_ managed!"

Gaster blinked in surprise. "Me?"

Asgore nodded eagerly. "You came out with me when no one else would dare to. You found out that magic caused the plant to grow. If that's right, then we'll be able to farm! And now we actually have a plan on how to rebuild!" He smiled at Gaster. "You've helped us out so much, and you didn't even need to, Gaster."

Something in Gaster squirmed uncomfortably. The way Asgore spoke made him sound charitable, when really he was just… _selfish._ The schematics were from boredom. Going out on this expedition was just to see if there were any other skeletons. He opened his mouth to say that, but…even if he had the words, the gratitude in Asgore's look would have rendered him silent regardless.

He sighed as he looked down at his hands, then began to sign as Asgore started to turn back to the water caves.

"Wing Ding," he translated.

Asgore turned around curiously. "What?"

Gaster swallowed and signed his name again. "Wing Ding. It is…it is, er, my…my given name."

"Wing Ding," Asgore repeated. He didn't have the suppressed laughter most had when saying that awful name outloud. "Should I call you that instead?"

" _No._ Definitely not," Gaster said quickly. "But, er…I figured…you should, er, know."

It was a poor trade for the compliments, certainly. But…well, it had to do for now. Until Gaster _could_ do something not based in his own self-interest.

Asgore smiled at him. "Thanks for telling me," he said, then adjusted his bag on his shoulders. "Now, come on! I'm sure we can make it back to the camp before too late."

Gaster adjusted his bag's straps as well, but glanced back out over the magma. Very far away, on the other side, he could just barely make out a little glimmer of white. That must be the Barrier.

He frowned. Well, sooner or later, they'd have to take care of that. It wasn't like they could _really_ stay down here forever.


	7. Appointed

Fifty years passed—not so long for monsters, but long enough for their fears of another attack to subside. Things weren't like the surface, no; there had been quite a lot of work done to pave and shape the caverns around them into something habitable, and, in the interest of space, their buildings mostly comprised of tent-like structures rather than actual _buildings_. The king and queen had a proper house, of course, but it was roomy and always open to guests.

But the cavern was temperate and spacious enough to live in. And, most importantly, it now had a real name: _Home._

The king wasn't great at names, but this one _did_ boost morale terrifically. And, as time went on, Home began to live up to its name. Families were growing, businesses were starting to pop up, and, truth be told, things were starting to get a little crowded at this point. But, _finally_ , the monsters had become comfortable in their new situation.

And, surprisingly enough, so had Gaster.

Naturally, things weren't _ideal_. Skeletons weren't big on being anywhere remotely crowded and, of course, there were days where he felt impossibly alone—it was only natural, given that he appeared to be the only skeleton who made it underground. But there was hardly time to dwell on that; his time had been all but eaten up with setting up farms, devising puzzles _just_ in case of an attack, and, of course, learning the language. He was quite fluent in it now, mostly thanks to chatting with Toriel.

In his time between projects, he read _voraciously_. It had taken a few years for him to be able to really read the language, but once he could, he couldn't stop. _Especially_ scientific books; he'd exhausted Toriel's supply within a couple years, and resorted to searching in Waterfall (he hoped Asgore came up with a better name for that place soon) for ones that had fallen from the surface.

Even with all of his reading, though, there was no answer to _how_ they had grown the flower so long ago. So, with the city built, the farming methods stable, and puzzles completed, he finally had time to do _research projects._

* * *

This one, like many others, started in the market.

"Well, if it ain't that ol' bag of bones!" Gerson called out as Gaster approached.

With no battles to be fought now, the turtle monster had turned to agriculture and was surprisingly good at it. As for him and Gaster, getting Asgore back to the camp in one piece had apparently assuaged any doubts about the skeleton. He teased Gaster quite a bit, but Asgore had assured that it meant Gerson liked him.

Gerson leaned against his stand as Gaster weaved through the crowds of shoppers. "So whaddaya want?"

"Just a crab apple," Gaster replied easily as he dug out a few small lumps of gold—their currency down here. He paused, then smiled a bit. "Er, actually, how about two? This last batch has been…" His hands fluttered as he searched for the word. "… _exceptional._ "

"Well, y'know what? Have the second one on the house," Gerson said as he winked his good eye. "After all, you're nothin' but skin and bones—without the skin! Wa ha ha!"

Gaster managed a smile at the _very original_ joke as he set down a bit of gold. "Yes, funny. Thank you, Gerson."

He quickly made his way out of the market, dodging a few children running past. Soon enough, he reached the living area and gratefully slipped into his own tent. He let out a breath, relieved to be away from the bustle, and took a moment to look around his own home.

It was tiny. And cramped. And it could do with being a bit farther from his neighbors.

But, really, it _did_ suit him nicely.

He moved carefully around discarded books and half-grown plants to set one of the crab apples on his table, then made his way to a bone set in the corner. He crouched down to examine it, taking a bite of the other apple as he did. It was still quite solid, _amazing!_ He stood up and jotted down a few quick notes before sitting in front of the whole apple.

Now, he hadn't tried to sprout anything bigger than echo flowers or sea grass, but…if he focused enough of his magic, he could…

"Gaster? Are you home?"

He looked up in surprise as he heard Toriel. _Oh!_ Of course, today was one of their book meetings! Thinking quickly, he bit down on the apple and held it in his mouth as he hastily began to clear away papers and remnants of other experiments. "Ye'! Co' in!"

There was a moment's hesitation, and then she pushed the tent's flap aside. "My friend, are you-?" She stopped and giggled as he looked up, apple still between his teeth. "Oh, I am sorry. I did not realize you were getting to the _core_ of your work."

Gaster shook his head with a smile as he took the apple out of his mouth. "Hello to you, too, Toriel." He set the papers down onto a small stack of books, then gestured to the chair. "Here, sit, make yourself comfortable. I will make some tea."

Toriel followed him instead, looking around the little tent. "You…seem busy, Gaster."

"I have been!" He searched around for two clean cups as he spoke; Toriel took the opportunity to look over his cooking area, which seemed…surprisingly clean.

"Have you been eating?" she asked. He waved his half-eaten apple in reply, and she huffed. "Something _more_ than an apple."

"An apple is all I need," he said as he finally pulled out two mismatched tea cups and saucers.

Toriel shook her head as she took the kettle and filled it with water. "I should have brought you a pie. You'll let yourself dissolve if you are not careful."

Gaster chuckled. "Remember, I am not a monster. My metabolic needs are different." He watched as she prepared to use fire magic. "Careful."

A slightly-too-big blast of fire hit the hob, making her jump in surprise. She sighed. "It keeps _doing_ that. I cannot tell you how many pies have been ruined because of it."

Gaster looked over at her, barely suppressing a grin. He'd wanted to keep this to himself for now, but…well, this _was_ Toriel. "You know, I may be able to tell you why." He set down his apple and gestured for her to follow him. "Here, look at this."

Toriel followed curiously, then blinked at the bone in the corner. "Is…is that one of your attacks?"

Gaster rocked onto his heels with a grin. "Yes. I summoned it a week ago."

"A _week ago_? That…you must be drained!"

His grin widened. "I am _not!_ Quite the opposite, in fact."

Toriel frowned back at him. "But why are you even doing this?"

"Because I am writing a…a…" His hands fluttered excitedly as he tried to get the words out. "I am writing a _thesis!_ "

Toriel's brow furrowed. "A…thesis?"

"Yes!" Gaster's hands were practically a white blur as he spoke. "You see, I have a theory. I-I believe that magic is more…more…more _concentrated_ down here! You see, up on the surface we were…er, it was, er, it was an open space! Which meant that our magic could, could…what is the _word_? Di-di-disperse! Yes, it could disperse into the surrounding area. _But_ , down here, we are in such a…such a confined area that our magic has nowhere to go. So that extra magic, er, it, er…it channels? Yes, good enough, it channels through us!"

Toriel blinked. "I…do not quite understand."

Gaster grinned as he leaned in closer to her. "We are _stronger_ down here. Your fire magic, growing plants…look!" He pointed up to a patch on the roof. "The first bone I summoned, it went right through! Now, I was not terribly strong above ground, so that lack of control is unheard of for me!" The kettle whistled, and he motioned for Toriel to sit as he went to prepare the tea. "I think I have finally compiled enough evidence to do a real thesis, and then _all_ of us can figure out how to best use this new strength to our advantage. Imagine how much further we'll progress!"

Toriel watched him for a moment, smiling a bit as she sat down. "I think you are onto something, my friend. And…you know, it ties in to what I came here to tell you."

"Oh? Have you found a new science book?" Gaster spooned tea into each cup before pouring in the water.

"No, it…is actually about Asgore."

Gaster smiled as he stirred. "Please tell me he is getting rid of that silly beard."

"It is not silly!"

Gaster raised his browbone as he looked over at her. "Toriel, you know I hold Asgore in the highest regard. I think he is the kindest, friendliest monster in the underground, and I consider it a great honor to be his friend." He turned back to spoon in some honey. "His beard is a little silly."

"Oh, stop," Toriel laughed as he brought her cup over.

"Fine, if it is not about his _not-silly_ beard, then what is it?" Gaster returned to the hob and, after making sure it was cool, leaned against it as he took his apple.

Toriel blew on her tea. "Well, surely you have noticed that things are getting a little… _snug_ here."

"I have. Why, the other day, one of my neighbor's children rolled right in here."

Toriel snorted, almost inhaling her tea. Once she stopped coughing, she said, "Well, Asgore is suggesting we start expanding out. After all, we do still have quite a lot of untapped territory."

Gaster nodded as he took a bite of his apple. "A wonderful idea. I am fully behind him."

"Yes, I expected you would be," Toriel said with a small smile. She looked down at her cup for a moment. "Of course, there will be…quite a lot of operations that will need to be carried out. Mostly in terms of power, but also equipment and structures and the like." She watched him as he nodded with each thing she named. "So…Asgore has decided to appoint you as the Royal Scientist."

The apple fell to the floor with a _thud_.

"No. Oh, god, no."

Toriel blinked a few times. "Wh-what?"

Gaster shook his head sharply. "I-I cannot. I absolutely _cannot._ "

"That is not—"

"I-I am hardly educated, Toriel!"

"You are writing a thesis!"

Gaster he held his skull as he shook it. "I-it…That is a _hobby._ I am not trained! We did not even have a university in our village!" He brought one hand down to cover his mouth as he shook his head again. "Tell Asgore I am flattered, but I _cannot._ "

Toriel was silent for a few moments, looking down at her tea. Finally, she looked back up at Gaster.

"Cannot, or do not want to?"

"What?"

Toriel sipped her tea. "If you do not want to, then that is fine. I know my husband, and he will not make you do something you do not want to do. But…if you are saying you _cannot_ , I must disagree."

Gaster stared hard at her. "You cannot disagree with _facts,_ Toriel."

"What facts? _These_?" she asked, gesturing to the notes scattered on the table. Gaster let out an annoyed grunt as he began to pace the length of the tiny tent.

"They are _scribblings._ You cannot even _read_ them."

"Then how about the structures around us? Or the puzzles in the ruins?" Toriel sighed. "Do you not want to do it?"

Gaster's hands moved jerkily. _I don't know._

" _Do you not want to do it?"_

 _I DON'T KNOW._

"Wing Ding!"

Gaster stopped and grimaced. He always forgot that Asgore had told her his name. He drummed his fingers on the hob for a few moments, then stalked over to the door, grabbing his jacket. Toriel immediately got to her feet.

"Gaster, where are you go—?"

" _I am going to speak with your husband!_ "

* * *

Ordinarily, Gaster was very friendly to the guards around the Dreemurrs' house, but today he stormed past without a word, sockets dark and jaw set grimly. He needed to talk to Asgore _now._

As usual, the king was out in the very small garden in the front. Nothing much grew there, but it didn't stop him from trying.

" _Asgore!_ "

Asgore looked up with a smile, though it abruptly died as he saw the look on Gaster's face. "Gaster, is everyth-?"

"Everything is not all right," Gaster snapped, hands moving wildly. "Toriel said you are appointing me Royal Scientist!"

"I said you will not if he does not want it!" Toriel called as she came into the garden. Asgore groaned and covered his eyes.

"It was supposed to be a surprise, Tori!" he said as she walked over.

"He hates surprises, you know that," Toriel retorted.

"And I am _very glad_ she told me," Gaster spat. He sucked in a breath and drew himself to his full height, nearly meeting Asgore eye-to-socket. "I cannot accept this, Asgore. It is impossible and…and a foolish idea on your part. Surely there is a much more promising, _credited_ scientist from the college who can…can do whatever a Royal Scientist would do." He gave a huff, then turned on his heel and started to walk back out.

Asgore sighed. Just as Gaster was about to turn out of the garden, he called, "I think you'd be really good at it, Gaster! Degree or no degree!"

Gaster stopped and swallowed. Asgore was merely playing to his ego. He needed to stand by his decision. Even so…he was curious. He glanced over his shoulder at the royal couple. "Why?"

Asgore took a few steps toward him. "Well, you're resourceful. You think things through, and you can get your ideas out to other people…"

" _Please._ I can hardly spe—"

"Gaster, you speak better than _I_ do at this point," Asgore said with a chuckle. He looked up at the skeleton, then let out a breath. "The fact is, we _need_ to expand. And for that, we need a plan. You're the most innovative monster I know, and…and I just have this gut feeling that you're the best fit for this job."

Gaster dragged a hand over his face. _How_ was Asgore always so convincing? He shut his sockets and let out a quick breath.

"One year."

Asgore's eyebrows rose. "What?"

Gaster clasped his hands behind his back. "I would like a year before we really consider this. I-I am writing a thesis right now, and I should finish it within the year. _Then_ I would like the university to look it over. And _if_ —and, really, Asgore, this is a large _if_ —it is deemed acceptable by them, then…then I will agree to be Royal Scientist."

Asgore stared at Gaster for a moment, then his face split into a huge grin. He gave Gaster a strong, friendly clap on the shoulder. "You see? This is why you're perfect for the job."

Gaster gave a tight smile. "A year, then?"

Asgore nodded. "Yes, my friend. We'll revisit this in a year."

* * *

rue to his word, it was a full year before it was brought up. It was also the busiest year of Gaster's life. While the experiments and study had been done more or less for fun before, throughout the year he threw himself into his research, trying to glean every bit of information he could about magic and the Underground from his books. It was hard, and he was fairly certain it nearly killed him

That said, it was tremendously satisfying to bring the completed thesis to the University. And, while he was certain there was a _bit_ of pressure from the king affecting the decision, it was even _more_ satisfying to hear that he had passed.

So now here he was, one year and one degree later, hands shaking as he tried to tie a tie around his neck without a mirror. There was a small courtyard near the royal home, with a large balcony looking out over Home and the other areas. It'd be swarming with people soon, but for now, Gaster was blessedly alone to gather his thoughts and unsuccessfully manage his tie.

"It looks as though you are having some trouble, my friend."

Gaster jumped nearly a foot off the ground, then shook his head as he heard Toriel giggle behind him. He turned around with a smile. "Surely a queen should not scare her subjects like that." He glanced over her long purple gown, a great deal different than the simple dresses she usually wore. "You might have ruined your royal attire."

"And then I would look as disheveled as you," Toriel shot back, then beckoned him closer. "Let me help you with that, _Doctor_ Gaster."

Gaster groaned as he stepped forward. " _Please_ do not start."

"Well, you _did_ earn your doctorate," she said with a shrug as she began to loop the tie around. "And as Royal Scientist, people will begin calling you that, just as they call Gorey and I 'King Asgore and Queen Toriel'."

Gaster sighed. "I still do not like it. It feels… _unearned._ " He shook his head as Toriel finished with the tie. "Where is, er, _Gorey_?"

"Finishing his speech," Toriel said as she leaned against the railing, patting down her ears. "He wants to make sure it is perfect for you."

"That is the problem with you monsters. Everything needs to be a spectacle," Gaster said bitterly as he stood beside her. "I am able to count the number of celebrations the whole village had throughout my life on two hands. You all throw parties whenever anything remotely interesting happens."

Toriel laughed lightly. "I think you might be nervous. You seem perfectly content to be counted with 'us monsters' when you are relaxed."

Gaster sighed, shoulders slumping as he leaned against the rail. "I am. I do not like being so… _public_? Is that right?"

"Not quite, but I understand what you mean."

Gaster shook his head. "I do not have to speak, right?"

Toriel smiled gently. "Not a word."

"And he will…he will not use my full name?"

"You will be referred to only as Dr. W.D. Gaster, like we agreed."

Gaster sighed. "I suppose that is the most I could ask for."

Toriel reached a paw over and squeezed his humerus gently. "It will be fine." She smiled as his sockets met her gaze. "Stay calm, my friend; I know you have doubts, but you _have_ earned this. Asgore and I both truly think this is what you were meant to do." She gave his arm another squeeze before drawing away. "Speaking of Asgore, I must go check up on him. We'll both be back before the ceremony."

Gaster nodded, then watched her run off toward the garden. He sighed as he looked out over the expanse of the Underground. He'd be in charge of the science and technology of all of this after tonight. He'd be responsible for getting them spread out throughout the area.

 _Royal Scientist W.D. Gaster._

The title was strange, but he supposed he'd need to get used to it. He'd gotten used to everything else down here, after all.

And he'd be preoccupied with making the rest of the Underground livable. If they wanted to tame the wild extremes beyond home, they would need power. Surely using magic would suffice for the first round of buildings, but for everyday life? Power was essential.

He squinted off to the distance, just barely seeing the red glow of Hotland from here. It'd been a while since he'd been that far, but the image of the roiling molten rock had never quite left the back of his mind.

Neither had that desire to tame it.

He blinked and let out a little chuckle. Of _course_. There it was. He hadn't even officially been appointed Royal Scientist yet, and he'd devised his plan for powering the Underground. _Geothermal energy._ He could—and _would_ —tame the magma.

And so, after the ceremony was finished and the festivities were over, the Royal Scientist, Dr. W.D. Gaster, set to work on what would be his greatest creation: The Core.

* * *

 **End Part 1.**


	8. Laboratory

**Part 2: The Core**

* * *

"Dr. Gaster, should we bring the test tubes?"

" _Obviously_."

"Dr. Gaster, I've got this microscope, but it's kinda old…"

"We are bringing all of the science equipment!"

"Dr. Gaster, what about the couch?"

"Of _cou_ —wait." Gaster had to stop at that one. He turned and frowned at the interns who were holding up the couch. "Why would we need the couch? We are moving to a lab, not a living room."

One of the interns shrugged, his wings flapping lightly at the motion. "Well, it's nicer to sleep on than the table."

The other one nodded as well, her ears swaying. "And we don't want you having back problems!"

Gaster rubbed his temple. "Fine, yes, we will take the couch." He checked his watch, fingers fluttering as he noticed the time. "But be quick!"

He gathered the last few notes and set them into a folder before looking at the swarm of interns running around the old Royal House. Ten. There were _ten_ of them; he still couldn't believe it. Of course, rationally, it made sense. The University, while it had given him his doctorate, didn't have much in the way of hands-on post-grad work, so it had been _heavily suggested_ that he open up his work on the Core to a few interns to get them acquainted with scientific work. And, hopefully, the Underground would get a few more scientists out of the deal.

Initially, he agreed to three. But then a fourth _begged_ for a position, so…it became five. The sixth appealed to Asgore personally, and the seventh had a whole presentation on why she would be a great fit for an internship. So eight seemed like a good number. But his good will _stopped_ at ten.

But…well, they were eager and ready to learn, and there was something refreshing in that.

He winced as he heard something shatter, and a very quiet "Oops."

The refreshment didn't negate the fact he was at his wit's end with them most of the time.

He pointedly did not look at where the crash came from, instead looking at his watch again. He needed to _go._ _ **Now.**_ But…god, would _any_ of the equipment survive the move if he left now? He could stay a few more minutes.

So he did.

And, then, of course, he was _very late._

After a moment of panic, he pulled over his most promising assistant, a young dragon-looking monster (the one who had given the presentation).

"Erie, I need to go," he hissed to her. " _Please_ make sure everything makes it to the new lab with as little breakage as possible."

Erie gave him a thumb's up. "I'm on it, Doc, don't you worry."

Gaster gave her a small smile. "This is why you are my favorite. Er…do not tell the others I said that."

Erie mimed zipping her lips, and Gaster nodded before bolting to the door.

"Wait, Doc!"

He skidded to a halt, long limbs flailing to keep him balanced. "What?"

Erie pointed to a small, wrapped package on the table. "You told me to remind you about the present before you left."

Gaster blinked. "Er, yes, right. I did. Thank you, Erie." He grabbed the package and tucked it into his coat pocket, then gave the interns a wave before bolting out.

* * *

Hotland was teeming with monsters by the time he reached it. Somehow, he managed to slip through the crowd with little incident, and, breathless and exhausted, he stumbled into the Royal Tent. He leaned against a post, gasping in breaths as he tried to get himself together after running through the entire Underground.

"You're late."

Even with his sockets closed, Gaster recognized Asgore's rumbling baritone, and he waved his hand in reply. "Need…just a few minutes…"

"Gaster, Tori's been up there stalling for twenty minutes!"

Gaster sucked in a breath and let it out slowly. "You see…if you monsters did not need to make _everything_ an occasion…we would not be in this situation."

"This is the official _start_ of the _Core_ , Gaster!" Asgore argued. He frowned. "How are you even out of breath? You don't have lungs."

"I still breathe, Asgore! _You_ run from Home to here and see how you manage!" Gaster finally let out one last breath before standing up straight. He brushed off his black coat, then looked at Asgore. "There. I can breathe. Let us make a spectacle out of announcing the lab."

Asgore looked at Gaster for a moment, then gave him a little nudge with a smile. "I bet you secretly enjoy these."

"You are projecting on me," Gaster replied shortly. "Would I be late to something I enjoyed?"

"I just assumed you like making a scene."

"No. It is to punish you for making me do these things."

"Now _that_ isn't true."

Gaster gave the king a shrug before he turned to the tent's opening. He pulled aside one of the flaps to peek out at the makeshift stage in front of the lab.

Even if she had been stalling for twenty minutes, there was no way of knowing with the way Toriel spoke. She was calm and cool, without a single stammer. If he didn't know better, Gaster would think that this was planned. He glanced back at Asgore with a smile.

"You know, this could have been worse."

Asgore raised an eyebrow. "I'd like to know how."

" _You_ could have been the one stalling."

He _knew_ Asgore was fighting a smile, even as the King shook his head.

"I'd like to remind you _who_ funded the Lab you're getting," Asgore shot back, though there was no bite in the statement. Gaster waved a hand.

"I know, I know. I am enormously grateful." Asgore raised an eyebrow at him. "I am! I am only good for blueprints and experiments, not getting actual structures built." He glanced out at the stage again. "And besides, there is something even worse than you stalling."

"Oh?"

Gaster grinned. " _I_ could have been the one stalling." He nodded toward the stage. "Regardless, we should help her, I think. Let us go."

* * *

The opening ceremony was the same as all the other monster celebrations. Asgore gave a rousing speech while Gaster stood to the side, looking important and not saying a word. Toriel stood with him, switching between watching her husband adoringly and whispering silly things to Gaster to try and make him break his stoic façade.

And then, of course, once the ribbon was cut, there were _festivities._ Not in the lab, thank _god_ , but just outside of it. Monsters milled about, trying to talk to Asgore about this thing or that. Gaster shook a lot of hands—he didn't know _why,_ he'd met all the same monsters at the _last_ event. There was food and music and dancing and all the other things that monsters enjoyed, but Gaster didn't.

He knew it was all fun, but there was just… _too much._ Too much noise, too much crowd, too much _everything._

Skeletons liked _quiet._

So after what had to have been his hundredth handshake, Gaster took the chance to slip into his lab. He shut the door behind him as quietly as possible, leaning against it with a sigh.

Moment of truth now.

He felt his way around the wall before landing on a switch. He sucked in a breath and moved his free hand to form one word.

 _Please, please, please…_

He flipped the switch up, sockets widening as the lights flickered on. A triumphant laugh bubbled out of him.

It _worked!_

He walked into the lab, looking around breathlessly at the clean white walls and gleaming metal tables. Of course, he'd designed the building and figured out how to use the magma to power the lab, but…well, everything up to this point had been experiments. There hadn't been any real, operational structures, not until right now _._

He leaned against one of the tables, staring up at the light bulb overhead. He'd powered one building. Now he had to power the whole Underground.

And he was starting to think that he could do it.

He looked up in alarm as he heard the lab's door open. "I am sorry, but civilians are not…" he trailed off as Toriel poked her head in with a smile, then returned it. "Well, I suppose the _Queen_ does not need any kind of clearance."

"You are absolutely right about that, my friend," Toriel said with a wink as she shut the door behind her. Gaster's browbone rose.

"You are running away from the party? I thought monsters loved parties," he teased as he walked over. Toriel shook her head as she set her little silk purse on one of the tables.

"Believe it or not, some of us get tired of crowds on occasion," she said, then looked around the lab with a smile. "And I had to get a look at what all of our hard work has given us. This is…amazing."

"I _know_!" Gaster gushed. "Look at how much light we have! It is nearly like being above ground again!" He waved at the lightbulb overhead. "Soon enough, _every house_ Underground will have light like this! We will fit New Home first, and then I think Waterfall—it gets very dark there. Hotland can wait awhile, so Snowdin will—" He stopped as Toriel giggled.

"Gaster, my friend, we need a Core first."

"Well, obviously. But we need to think of the, er, _big picture_ , is the phrase?"

Toriel nodded, still smiling. "Yes, I suppose we do."

Gaster returned her smile, fingers fluttering slightly. "You, er…your speech was very good, considering I was late. You are very good at, er… _improvising._ "

"Well, not _that_ good."

"Do not be modest."

"I really am not." She smiled and opened her bag. "Here, look, I will show you my secret weapon."

Gaster's browbone furrowed, and he stepped forward. Toriel held up a stack of notecards and separated them into two piles. She gestured for him to look, which he did. One stack said "Laboratory Speech"; the second said "If Gaster Is Late."

"You knew I would be late?"

"You have been late to _everything_ since you have started working on the Core," she said with a smile as she tucked her notes away.

Gaster shrugged as he leaned against the table. "Well, I _do_ think giving us power might be a _bit_ more important than standing on a stage..."

"Ah, no, you cannot say that. We made no secret that being Royal Scientist would include engagements. One day, you might even have to _give_ a speech."

"Toriel, you are a _cruel_ monarch."

Toriel smirked. "I am a just one. The public deserves to hear from their public servants, scientists included." She looked up at him, then frowned curiously. "Wait a moment." She reached forward and lightly touched Gaster's sleeve. "Is this…a black _lab coat?_ "

Gaster looked down at her hand, then half-smiled. "Er, yes, actually."

"But…Lab coats are white, are they not?"

"Well, mostly yes. I have had to have it custom-made, thanks to your husband."

Toriel frowned. "What did Asgore do?"

"He knitted this for me a few months ago." Gaster lightly touched the collar of his white sweater. "And I am very fond of it, but…well, with my, er, _complexion_ …" He gestured to his skull. "And the white sweater, and the white lab coat…why, I disappeared when I visited Snowdin!"

Toriel snorted, and a braying laugh escaped her before she could stop it. Gaster grinned. It wasn't often anyone could get her to laugh that hard, so it always felt like an accomplishment.

After she composed herself, she gave him a nod. "Well, it suits you."

He blinked in surprise. "Really?"

"Yes, Dr. Gaster. Black makes a scientist look very…" She grinned. " _Smart._ "

"Oh, _god_." He shook his head with a laugh as she giggled. "Threatening me with public speaking and assailing me with puns. You are a _tyrant._ " He stood up straight, glancing down as something jostled in his pocket. _Ah_ , right. "Oh, I nearly forgot." He pulled out the little gift and held it out to her. "For you."

Toriel looked down in surprise. "Oh?" Her brow furrowed. "I do not understand. Why are you giving me a gift?"

"Well, if memory serves me right, it was around this time seventy-odd years ago that you taught me how to speak." He smiled as he took her hand and set the gift in it. "I figured this was the least I could do to thank you."

Toriel stared down at the gift, clearly torn between wanting to open it and politely saying she couldn't accept. Eventually, she very carefully slipped a claw under the paper and opened it.

Beneath the wrapping paper was a small, handsomely bound book. A title was engraved in strange characters—Gaster's alphabet—with "SKELETON STORIES" written in Monster underneath.

Toriel looked the book over curiously. Gaster's hands fluttered as he tried to gauge her reaction, suddenly having second thoughts.

"I thought…well, these are…erm, I think your term for them would be fairy tales?" He looked down at the book. "They were, er, stories I was told when I was very young." He shrugged. "I may have taken a few liberties on parts I could not remember, but…but I thought you might find them interesting, so I…translated them."

Toriel remained silent, still looking at the book. Gaster swallowed, hands half-forming the anxious words in his skull. He cleared his throat.

"I…I mean, if, if you do not like it, you can donate it to the library. I-I am sure so—"

He was cut off as he was pulled into a squeezing hug.

"My friend, it is _perfect_ ," Toriel said. She let out a soft laugh as she let him go. "I have not gotten such a thoughtful gift in a long time."

Gaster blinked, and a wide smile started to spread across his face. "Really?"

Toriel nodded, already flipping through the book. She looked up at him with bright eyes. "I will start reading it immediately."

Gaster took a step closer, peering over her shoulder as she turned to the first page. "I would actually recommend reading the third story first."

"Oh? Why is that?" Toriel glanced back to look at him curiously.

"Well, I have organized them in…a sort of rational order. But…" He gave her a slightly sheepish smile. "'The Femurs' March' was always my favorite as a child."

Toriel smiled warmly at him as she nodded. "Then I will be sure to read that one first." She returned her gaze to the book. "I am already thinking of questions for when we next meet."

"Well…I see nothing stopping you from asking a few now."

Toriel glanced back at him again, already opening her mouth to ask a question. Her eyes dimmed a bit, and she merely let out a sigh instead.

"The party. I need to go back," she said as she closed the book and tucked it into her bag. "I am sure my absence has been noticed gone by now." She glanced up at him. "You ought to come back out as well."

She patted down her ears as she walked back to the door. His shoulders slumped ever so slightly as she drew away, a little disappointed at the end of their…moment?

But duty called. For both of them.

She opened the door, then glanced back at him. "Gaster? Are you coming?"

He straightened his spine and gave a small cough before he gestured at the space behind him. "In a few minutes. I need a bit more time with my lab."

Toriel smiled. "Of course. I will leave you two alone," she said with a wink, then made her way out the door.

Gaster watched her go, that disappointment still gnawing at his center. But he pushed it down as he stared up at the light overhead. There were more important things to focus on. The first step to powering the Underground was a success, but there were still were still so many to go.

It was time to get to work.


	9. Complications

"Morning, doc!"

Gaster jolted up in alarm. He looked around with a frown. Where was he…? He looked up as Erie laughed.

"You fell asleep at your desk again," she said, setting a mug of coffee in front of him. "There ya go."

Gaster stretched his back, spine popping, and he rubbed his temples as he looked at the coffee. "Are the others here yet?"

"Nope, I came in early." She pulled over another stool and sat down, holding up a little notebook. "I thought we could go over some of what we need to get done before we get power over to Waterfall."

Gaster held up a hand as he took his mug. "In a moment, Erie." He grimaced as he looked down at the coffee. He _hated_ the stuff, but tea didn't have quite the kick needed to keep him running as work on the Core grew more hectic. He gulped down a few mouthfuls, then gestured for her to talk.

"All right, so we're at peak levels of electricity in New Home. But we'll need to triple that to power all of Waterfall. I know we're already expanding the Core, but there's no way we can get that much power with just automation."

Gaster shook his head as he tossed back the last bit of coffee. "We are already getting workers. Asgore has promised the Core will be a…er…what is the phrase?" His hands moved vaguely. "A work initiative."

"All right, so in _that_ case, we'll have to review the schematics to make sure the machinery's simple enough to use without having a doctorate in engineering," she said, jotting down a note on her clipboard. "Next problem: the Core's already starting to get hot, and the expansion's gonna mean even more heat. That could get dangerous."

Gaster nodded as he rubbed his forehead, morning fog starting to clear. "I will start thinking of methods to cool it."

Erie gave him a big smile. "You _could…_ but I _have_ thought of a method that could work. I have some diagrams ready."

Gaster raised his browbone, then smiled and shook his head. "You must sleep less than I do, Erie."

"Nope, I just have a schedule," she said with a grin. "All right, back to our discussion. We really ought to test the Core's safety system. I know we have an automatic lockdown in place if there's any overheating, but Marsel worked on that and he's prone to overlook bugs, so I was thinking we could—" She stopped as Gaster held up his hand with a laugh.

"Give me a moment to catch up!" he said. "Let us save the safety discussion for when everyone comes in. You said you had a plan for cooling down the Core?"

Erie's expression brightened. "Yes! I mean, it's not _perfect_ , but it should do until we can create a better system." She flipped through the pages on her clipboard, then held up one of a simple map. "See, Waterfall has several waterways that lead to Hotland, but _two_ of them—" She used her pen to point to two of the blue lines. "—actually start in Snowdin. So the obvious answer is to find a way to get the icy water through Waterfall into Hotland. Obviously insulated pipes are a must, but that could still heat the water. So…" She flipped the page to show a crude drawing of a machine spitting out squares. Around it was a series of neat little notes. "…I was thinking if we could find a way to condense the snow in Snowdin to sub-zero ice cubes, then the water should stay cold!"

Gaster listened intently, a small smile on his face. He held out a hand for the clipboard, which Erie eagerly handed him. He flipped through the pages, studying them intently. "I think I like this idea, but…it will take time to fully complete," he said slowly. "A rudimentary version may be operational in time for the new expansion, but your internship ends after Waterfall is powered."

"Well, I _was_ planning to bring this up later on, but since the opportunity's presented itself…" Erie took a quick breath and straightened her back. "Dr. Gaster, if you have a position open, I'd like to stay on after my internship has ended."

Gaster smiled and handed her the clipboard. "I will…what is the phrase? I will do you one better," he said. "I know it is short-notice, but starting today, I would like you to start working as my assistant."

Erie's eyes widened, and her tail whipped around her seat. "Your…your _assistant?_ "

Gaster smiled and gestured to her clipboard. "Yes. I think you have proven yourself to be quite adept at organization and management, and your work just now—in addition to the attention to detail you've shown throughout the Core's development—shows that you have a passion for the work." He smiled. "I think we will start you with the same hours for now—do not look at me like that, Erie, you still have your doctorate to finish—and after you graduate, I will have you work full-time." He gave her a wink. "And eventually, possibly a partnership. After all, two Royal Scientists are better than one."

Erie pressed her claws to her mouth. "I-I… _thank you,_ Dr. Gaster! I…I'll get to work right away, I can start working on a prototype for my idea if you want, or I can go and check out the steam release vents or-or…"

Gaster chuckled. "First, I think you ought to take a few moments to breathe. I will meet you and the others at the Core."

"Yes…yes! I'll see you then!" Erie said, gripping her clipboard tightly and nearly falling off the stool as she got off. "This is a great decision, Dr. Gaster! You won't regret it!"

Gaster smiled a bit as she took off out of the lab, then looked down at his mug. Time to clean up and get to work, he supposed. The Core wasn't going to build itself.

* * *

Work continued as usual. Gaster had every intention on checking the safety system, but immediately on walking into the Core, three interns told him how the manual operations for the future workers weren't working. So that was the priority, and anyway, Gaster was confident in Marsel's work.

He was hard at work trying to get the wires back to where they needed to go—not his strong suit—when he heard a few of the interns whisper to each other. Probably figure out how to ask for a break. He'd let them go once he fixed this blasted…

"Excuse me, Dr. Gaster?"

The soft voice caused Gaster to bolt up in alarm, skull hitting the top of the machine with a _clang_. He rubbed it with a grimace, checking for cracks, then turned around.

"Tor—er…" He glanced at the interns. "Your Highness," he amended, dipping his throbbing head respectfully. Toriel covered her snout with her paw, trying to hold back her giggles.

"I'm very sorry, Doctor. I did not know my greeting would _rattle_ you so much."

A few of the interns chuckled at that, most out of politeness. Gaster smiled and shook his head.

"I have had much worse," he said, then looked up. "Er, am I needed?"

Toriel's mouth turned up, but she lifted her head regally. "Yes, I would like to talk to you alone, if you do not mind."

"Of course, your highness." Gaster turned. "Tryce, if you could try to make sense of those cords?"

"Of course, Dr. Gaster!" The dinosaur monster quickly went to the console and got to work.

Gaster watched him for a moment, then gestured for Toriel to follow him to a more secluded part of the Core. He glanced back at the interns—all of whom were watching him while Erie called for them all to focus on their work—then leaned in to quietly ask, "So what is wrong?"

Toriel grinned. "Well, I do not know if you had it in your schooling, but in our society, we have a thing called 'playing hooky'. And I think you ought to try it."

Gaster frowned. "I do not understand."

"You have been working too hard, _far_ too hard. You need a break!" She gestured to him. "You cannot even stand straight from hunching over all day."

Gaster straightened his back automatically. "Mild scoliosis was common with the Gasters. I am fine."

Toriel looked at him skeptically, then turned to the interns. "Excuse me!"

They all immediately turned to look at the queen, all eyes wide. Toriel smiled.

"Can anyone tell me the last time Dr. Gaster has left the lab?"

Gaster dragged a hand down his face. "Toriel, this is ridiculous. I leave at night like everyone else."

"Oh, you have _not._ He last left three days ago, Your Majesty!" Erie piped up. Gaster groaned. Of course she'd been paying attention. He met Toriel's gaze, grimacing at her "I knew it" look.

"There, so it is clear you need a break. So we will play hooky today," she said with a triumphant smile. "Queen's orders."

"You abuse your power, you know." Gaster sighed and shook his head, though his mouth quirked into a small smile as he did. "But I suppose that means I do not have a choice."

"I'm afraid not, my friend."

"Very well, then." Gaster walked over to the gaggle of interns, most of which were trying to look _very at ease_ despite the fact that the Queen was _right there._ "All right, listen, everyone. I will be leaving for a few hours, and I expect you all to keep to our schedule. So I will be back before you—"

"What?!"

Panic broke out among the interns.

"But what about the wiring for the console?"

"We need you to look at the preliminary structure for the next room!"

"Dr. Gaster, I'm worried about my calculations. I need to ask you…"

Gaster held up his hands with a laugh. "If I recall, all of you are _well_ into your post-graduate programs. I have faith that you can manage a few hours without me."

There was a moment of silence.

"Okay, but _really quick,_ could you just—"

"It's just _one_ equation, and I—"

Gaster held up his hands again. " _Quiet,_ please." He looked over the interns, browbone raised at their fuss. "Look, a majority of your questions can be answered by Erie. If she cannot answer them, then they can wait until I return. And if it is something that is threatening to blow up the Core, then follow our safety protocol." He gave them a smile. "Is that clear enough?"

There was a mumble of agreement, and the interns dispersed back to their work. Erie, however, came up to Gaster, eyes wide.

" _I'm_ in charge?" she whispered. Gaster half-smiled.

"Well, it seemed a suitable punishement."

" _Punishment_?"

"It is, after all, your fault that I have to go. If you had not…tattled, I think is the word, then the Queen would not be insisting I go out." As Erie started looking genuinely worried, he quickly added, "I am joking! Obviously, being the forward-thinking girl you are, I can only assume that you wanted to see what your new position entailed."

Erie grimaced. "Oh, _obviously._ "

Gaster patted her arm. "I would not have made you my assistant if I did not think you were capable. You will be fine."

Erie nodded, then took a deep breath and stood up straight before walking back to the interns, barking out orders. Gaster smiled as she began instructing the group, then returned to Toriel's side.

"There. Everything is settled, so we may 'play hooky' as per royal demand."

Toriel gave him a regal nod, then motioned for them to leave with a grin. Once they exited the room, she said, "Your interns are very fond of you."

Gaster sighed, pulling out his keycard to open one of the main exits. "They are like ducklings following their mother. I am surprised I convinced them to stay put, honestly." He hit the button for the door to shut and lock, then glanced at Toriel as they walked to the next door. "Where is Asgore?"

Toriel crossed her arms. "A fire broke out in Waterfall, and two neighbors are arguing over who caused it. I could not take the arguing any longer, I am afraid." She half-smiled. "I don't know how Gorey manages it."

"Asgore seems to have a truly extraordinary amount of patience," Gaster said with a little laugh as he opened the main door out to Hotland. "Luckily, arguments like that will soon be a thing of the past! We should have power to Waterfall in three months' time!"

Toriel smiled as they exited the Core. She turned, looking up at the grand building they had just left. "You know, everything about this is very impressive."

Gaster smiled proudly as he looked up. "I suppose it is a _bit_ impressive." He winked at her "Especially since the head of the project could not speak less than one hundred years ago." He clasped his hands behind his back. "So, what are Her Highness' plans for 'playing hooky'?"

Toriel smiled. "Well, actually, I thought we might visit Home."

Gaster's brow furrowed. "Home? But it is a…a ghost town."

"Perhaps, but I was always fond of it." She smiled at him. "And I think you could do with some quiet."

He shook his skull with a smile before dipping his head respectfully. "If it is what the queen wishes, then who am I to refuse?"

* * *

Home was much quieter than it had been three-quarters of a century before. While there were still a few who lived in the area, most monsters had moved out of the cramped little cave system. Many had gone to more remote places in order to rear their families, while others sought out areas with climates better suited to their bodies.

Their footsteps echoed through the stone-paved cavern, and Toriel visibly relaxed as they walked.

"It is nice to get away from the noise," she said. Gaster couldn't help but agree—he did still _technically_ live here for that very reason.

"I think, though, that I prefer Snowdin," he said as they walked into the now-empty hallways past the house. "It is a pretty area, and…" His mouth quirked up. "I do have some happy memories there from my first outing with Asgore."

Toriel smiled warmly at that, and she gestured toward a low wall. She laughed lightly as she sat. "Even though this is not Snowdin, I am sure this is still a welcome break from your ducklings!"

"Oh, yes. You know, it _is_ nice to not hear 'Dr. Gaster' four times in a row," he agreed as he sat beside her.

A silence stretched between them, not the least bit uncomfortable. That, he found, was one of the things he loved most about Toriel. Though they spoke, and spoke quite a lot, there was never any pressure to maintain a conversation. Why, half the time they spent together, each was reading a different book. But having her there was…

She interrupted his train of thought. "You know, speaking of ducklings…"

Gaster groaned. "Toriel, no."

"You do not even know what I was going to say!"

"I absolutely know what you are going to say! This is the third time you are starting this conversation, and I _still_ do not want to have it."

Toriel puffed. "I am trying to _help_ you, my friend. I mean, you're my age, right? Well into your hundreds…"

"Is playing hooky meant to be such a stressor?"

Another silence passed. This one was a little more uncomfortable.

"I worry about you," she said, voice soft.

Gaster blinked. "What?"

"I worry, Gaster! You lock yourself away for days, you put yourself in risky positions."

Gaster stared at her, then swallowed as he played with a loose thread on his sweater. "It is the nature of my job, Toriel."

"I know, but I just think that…that if you could just settle down with someone, it might prompt you to be a little safer."

Gaster managed a little laugh. "Even if there were a…a biological motivation for me to, er, _settle down_ , I do not think I would. I would be a horrid husband."

"Oh, you would not."

"Having someone at home would not stop me from staying in the lab for days on end or getting samples of magma," he said. "I have an Underground to power. That is my priority. And they would fall by the wayside for me. That would be cruel to them."

"You came out when I asked."

"That is different." He left it at that.

Toriel huffed. "It would be different with them, too. I mean, you don't see Asgore and I tethered to each other."

"Well, I do, but not in the sense I think you mean."

The barest hint of pink showed from under her white fur, and she gave him a little shove. He laughed, then looked down to his hands.

"You know…I have a question for you."

"Yes?"

"Though it may be rude."

"…yes?"

He was silent, trying to imagine the best way to say what he was thinking. "How did…you and Asgore…end up together?"

Toriel giggled. "That's not rude."

"That is because I skipped the rude parts."

Toriel blinked, then frowned. "Well, you may as well say them now."

Gaster waved his hands. "It is…I do not _mean_ for it to sound rude! You know my feelings on Asgore, he is one of my dearest friends. But…he is not so…well, not _as…_ er…well, I mean, _you_ are just so…so smart and beautifully composed and eloquent and…" Bit much. He should stop. "And he is…he is _different_."

"Ah. Yes, I suppose he is."

"So…how?"

Toriel made a face, and she etched a little pattern on the stone wall with her claw. "It…well, Boss Monsters were never very common. So there was very little selection for the royal family." She shrugged. "Asgore and I were, essentially, betrothed at birth. So…there was not much say in the matter of us getting married."

"I see…"

"Of course, because of that, I have known him since I was very young. He has always been sweet and kind and patient." She smiled a bit. "And, as we prepared for the wedding, I saw other sides of him. He laughs at my jokes, he listens to me prattle on about what I've been reading, he takes care of me when I need it…" She smiled widely. "And, most importantly, I know he will be a good father when we have a child."

While he had been listening fairly passively, that last sentence sent ice seeping down Gaster's spine.

"A… _child_?"

Toriel looked up. "Well, yes. Both Asgore and I have been talking a—"

"You can _not_."

Toriel frowned. "Excuse me?"

"I have done my research, Toriel!" Gaster's hands were everywhere, trying to get his explosion of thoughts into something coherent. "I know what happens when boss monsters have a child! You…you…" He could barely get enough air out of him to get the words out. "You will _die._ "

Toriel looked at him sympathetically, and she lightly reached out to pat his hand. "Gaster, we will all die one day."

Gaster pulled his hand away, getting to his feet and pacing as his hands jerked around. "But _you_ do not have to! You could live forever! _You_ , you could…there would never have to be a…a world without _you_!" Was he making sense? He wasn't sure. His thoughts were everywhere, but one was forefront: _Toriel could not die._

Toriel stared at him, a strange expression on her face. "Why…Gaster, this really is not something that concerns you…"

"It does! I am concerned!" he cried out.

"But it should not _matter_ to—"

"It _does!_ "

" _Why?"_

 _"Because I—_ " His hands moved, but his voice stopped. He stared at Toriel with wide sockets, and she stared back. The pitying expression that began to spread across her face said it all.

 _He had ruined everything._

He felt his ribs tighten, squeezing the air out of his chest as Toriel got to her feet.

"Gaster, I…"

He shook his head quickly, holding up his hands to stop her from talking. He jerked out a words—nonsense, stupid words to get himself composed—then let out a breath and stood up straight.

"You…you are right, Toriel. I have no right to dictate what you do," he said stiffly.

"Gaster, just…" Toriel reached out to touch his arm, but he quickly stepped back.

"I…I need to get back to the lab. The interns are waiting," he said quickly. "I will…I will see you soon."

Without giving Toriel a moment to speak, he quickly left Home.

Back to the Core. Back to stability. Back to _science._

* * *

He was extra productive once he got back into the lab, going so far as to dismiss the interns early so he could work without stop. The consoles needed fixing, the heat levels needed to be measured, the safety system…he couldn't work on, but he took notes of all the things that would need to be addressed with it.

He _worked._ And that kept his thoughts at bay.

But it couldn't last forever.

As the night drew on, he slowed down until he finally came to a dead halt, unable to work and unable stem the thoughts that had been battering away at his skull for hours.

 _He'd ruined everything._

He had one bright spot in this lonely life, and a stupid moment of emotion had gotten rid of that.

And it really was stupid. After all, emotions meant _nothing._ He had been wrecked when his village died, but what had that sadness done? Monsters died. Even in their new home, they kept dying. It didn't matter how sad he or anyone was, it still happened and he couldn't stop it. He couldn't stop her committing suicide by child, and he couldn't go back to keep from ruining what they had.

He clenched his hands into fists, thoughts still swirling and pounding in his skull.

But there were things he _could_ control. He had tamed nature. He had given New Home light. For god's sake, he was a _genius._ How many other monsters could do something like the Core in one hundred years? How many monsters could adapt and _thrive_ like he had?

By god, he would keep thriving, even if he had to do it alone. And by _god_ , so would the whole Underground. He would be _unstoppable._

He strode to the whiteboard on the wall of the room. In large, messy letters, he wrote one note for the interns to see in the morning.

WATERFALL LAUNCH RESCHEDULED TO NEXT MONTH.


	10. Miscalculation

By the time Gaster realized that moving the launch date was a _huge mistake_ , it was too late. Announcements had been made, hopes had been raised, and the Royal Scientist and his team had to find a way to fulfill those hopes.

So they might have cut a few corners.

That might not have been so bad, except that he had been a _horror_ to work with since his meeting with the queen. The friendly skeleton with a funny way of talking seemed to be gone, replaced by an impatient scientist constantly barking out orders and moving his hands in a way that suggested he thought everyone around him was an idiot.

For the most part, though, the interns chalked it up to stress. And while annoying, it wasn't really a problem. At least, not until the steam vents stopped working, and he insisted they fix it later.

So, as the Royal Scientist's Assistant, it was time for Erie to try and talk some sense into him.

She waited for the interns to be (grudgingly) allowed to go home before she approached him. It was harder than it used to be; the last time she'd stepped up to him with a breezy "Hey, Doc," had gotten her a glare that sent a chill through every scale.

He was hunched over his desk, scribbling intently. Erie sucked in a breath, then cleared her throat.

"Um, Dr. Gaster?"

" _What_?" he asked sharply, not even looking up.

She almost lost her nerve. Gaster was the Royal Scientist, after all, so maybe he knew best. But…before whatever happened, he'd talked about wanting to work together as equals. So she had to prove she was up to that challenge. She stood up straight.

"Dr. Gaster, we need to stop the expansion."

Gaster's hand stilled, and his shoulders stiffened. He was quiet for a long moment, then shook his head as he returned to writing. "No, we do not. You do remember that we have a deadline to meet, Erie?"

"Yes, but—"

"Then we _cannot_ waste a moment." He huffed. "We _should_ still be working. We could most likely finish early if we did."

"Gaster, someone's gonna get really hurt if we keep working like this!" Erie protested. Gaster waved a hand dismissively.

"It will be fine."

"No, I don't think it will!" Erie's tail thrashed around agitatedly, and she took the deepest breath she could. "Dr. Gaster, we need to push back the launch."

 _"What_?" Gaster finally whirled around, sockets wide. "I am sorry, are _you_ the Royal Scientist?"

Erie swallowed, doing her best to meet his sockets even as she felt his gaze boring into her. "No, but…but I know a good scientist should look out for others. It's not _safe_! Marsel's _still_ recovering from when he got scalded the other day, and you didn't even bat an eye! And…and the Core's overtaxing itself while only putting out two-thirds of its usual energy and…and…" She let out an annoyed grunt as she threw up her hands. "Honestly, I don't even know _why_ you changed the date!"

Gaster was silent for a long moment, an ugly scowl on his face. He huffed and turned back to his work. "You would not understand."

" _Try me_ , doc!"

Gaster stopped writing and let out a breath. "Because I knew we could do better. Waterfall needs power _immediately._ "

"But we can't doit _this soon!_ It's impossible!"

Gaster slammed his hands down on the table as he stood up. "If that is your attitude, you are free to leave the project," he snapped.

Erie froze. As he turned to face her, she could barely get her voice to work. "Wh-what?"

"You do not need to stay. No one is forcing you," he said coldly. "If this sort of pressure is burdensome to you, then perhaps science is not the route for you."

Erie blinked a few times to get her eyes to stop stinging. She shook her head. "God, what is _wrong_ with you? Why are you doing this?"

Gaster's jaw twitched. For a moment, his harsh expression shifted into something like worry, but he shook his head.

"I am doing this because I can," he said in a low voice.

"What?"

"Because I _can!_ " Gaster's scowl was back in place as he paced. "It was ridiculous of me to think we needed _three months_ to make an addition to the Core. It took me four nights to design Home! It took three months to build it _in its entirety!_ "

"But this is different."

" _Is it_? You were not there! You did not see what life was like after the battle, how much _I_ improved things! So _this_ is simple! Waterfall _will_ be powered by next week, and if you are _so worried_ —" He sneered the last two words out. "—then you may go! Pursue another career, because _clearly_ you are not the scientist I thought you were!"

Erie stared up at him, tears finally welling up in her eyes. Gaster quickly turned, shoulders stiffening. She quickly wiped her eyes and looked down at the ground.

"Am I…fired?" she asked, voice wavering.

"That is up to you," Gaster said gravely, not turning around.

Erie let out a shuddering breath, shoulders sagging. "Then I'll see you tomorrow, Dr. Gaster."

* * *

The next day wasn't much different than the day before. The clogged vents could wait, Gaster instructed, so work on power sources instead. So the interns did, and he worked twice as hard right alongside them.

They might have made more progress, except _Asgore_ called.

The king, naturally, was the one person the interns were instructed to _not_ hang up on when the phone rang, so Gaster grudgingly took the receiver from Tryce.

"What is it?" he asked dully. He wasn't as sharp with Asgore as he had been with everyone else who had tried to talk to him lately. He wasn't sure if it was because they were friends, or if he didn't want to bring attention to the conversation he and Toriel had had a few weeks ago, when he'd stupidly let his guard down.

"It's a matter of utmost importance," Asgore replied, voice very serious. Gaster shut his sockets as he leaned against the wall. He knew that tone.

"Is anyone dying?" he asked dryly.

"Well, no…"

"Then it can wait. Waterfall's launch date is-"

"Gaster, it'll take all of a half-hour," Asgore assured. "I'll meet you outside the Core."

Gaster groaned. "Asgore, _please._ "

"Utmost importance, Gaster." God, he could _hear_ Asgore's smug grin. It wasn't often the king threw his weight around, so he relished the opportunity when it arose, which was almost always seemed to be at Gaster's inconvenience.

Gaster huffed, though his browbone furrowed. "Will…Toriel be there?" Hopefully that didn't sound too timid.

"No, she's got a meeting with the Head of Education," Asgore said breezily. "Though if you want, I could ca—"

" _No._ " Too intense. Gaster cleared his throat. "That would just take more time. I will meet you outside." He quickly hung up the phone, then let out a breath before drawing himself up.

"Everyone!" he called out. The interns all stopped and looked up. The few capable of sweating wiped their foreheads; with the vents out, the Core had been getting a bit warm. "I have to speak with the King, _do not_ stop what you are doing while I am gone. I do not want to have to make up more time than necessary." He frowned as he got a mumbled response in return.

"We'll keep working, Dr. Gaster, don't worry," Erie said wearily from her place at one of the magma tubes. "We have a deadline, after all."

Gaster nodded shortly at her, then sent one last glare to the group before making his way out of the room.

Once he was away from everyone, he rubbed his skull with a groan. He was aware, on some level, of how awful he was being. But he _needed_ to finish the Core. He needed to prove that he hadn't ruined everything by letting his emotions get the best of him that day. This was the only way he could manage that.

He reached the Core's main doorway, making sure to put on a stoic face. As far as he knew, Toriel hadn't told him about his near-confession. That didn't make it any less awkward for _him_ , though. And Asgore wasn't stupid; he must have realized that Gaster and Toriel hadn't spoken in weeks. God, he hoped that wasn't what this was about.

Well, given the big grin Asgore gave him as he stepped out into Hotland, probably not.

"I swear, this'll be quick," the king said. Gaster huffed and pointed to his watch.

"A half-hour, that is all I can give you."

"I know, I know. We'll walk fast; Snowdin's not too far."

" _Snowdin?!_ "

Asgore smiled and started walking. Gaster frowned and followed after him as quickly as he could without running.

"Asgore, this really is not funny!" he shouted after the king.

"What I'm showing you is right on the edge of Snowdin!" Asgore called over his shoulder. "It's practically Waterfall!"

" _Why_ could it not wait?"

"Honestly? Because I wasn't sure when you'd come out again."

They were in Waterfall now, but Gaster was purely focused on catching up to Asgore. Asgore glanced behind him, then picked up his pace. Gaster gave up all hopes of not looking foolish and ran after him. _Damn_ Boss Monsters and their strength! His legs were longer than Asgore's, _why was he still slower?_

Abruptly, Asgore came to a stop, and it was all Gaster could do to stop himself from toppling over in the snow.

"Told you it was quick," Asgore said with a grin. Gaster signed a few impolite phrases his way, but Asgore didn't see. "But this is what I wanted to show you." He motioned in front of them.

Gaster looked up, then frowned and crossed his arms. "It is a house."

"It is!"

Gaster's frown deepened. "It is _lovely,_ " he said dryly. _"_ Now if you will let m—" He stopped as Asgore grinned at him. "What? What is that smile?"

Asgore's grin widened. "It's yours."

"What is?"

"The house. It's yours. I had it built just for you."

For the first time in several weeks, the sharp, harsh look melted off Gaster's face completely. He looked up at the house.

"It…why here?"

"Well, Tori mentioned that Snowdin was your favorite place in the Underground. So…I thought you'd like to live there. And I made sure it was a decent way from the rest of the town, since you like the quiet." Asgore looked expectantly at Gaster. "So? What do you think?"

Gaster blinked. The house was far too big. And _so_ far from the lab and the Core. Would he even be able to live here? He looked up at Asgore, then let out a breath before giving him a little smile.

"It is perfect."

Asgore beamed. "You really think so?"

"Of course. I will move right in after the expansion is finished," he said, then checked his watch. "But I really do have to get back."

"So do I," Asgore said. He winked. "But I figured we both needed to get out for a bit."

Gaster sighed and shook his head. Even so, that need to fix things, to _prove himself_ , had died down a bit. Perhaps he could be a little less… _awful_ to his interns. He gave Asgore a small smile.

"Thank you." He checked his watch once more. "This time, we can probably walk back."

* * *

The walk was…well, not _nice,_ since there was still the deadline looming over him. But he wasn't as angry this time around, so that was good. Even so, as they reached Hotland, he frowned.

"Do you hear something?" he asked Asgore.

Asgore's brow furrowed, and he listened.

"It sounds like a bell ringing," he said. "It's probably the school."

Gaster shook his head. "No, the school is in New Home. We would not be able to hear it. This sounds closer." He quickened his pace, Asgore followed.

"Well, whatever it is, it isn't stopping," the king pointed out.

"Obviously. It almost sounds like…" Gaster froze, his sockets widening as he felt dread building in his center. "Oh, _god!_ "

Without another word, he bolted. He ran full speed through Hotland, back to the Core. Along with the incessant ringing of the alarm was the loud blaring that signaled a full shut-down from overheating. So the alarm system worked, but… _where were the interns_? Evacuation protocol dictated that they meet by the lab, and _no one was there_.

He nearly fell against the console as he skidded to a stop at the Core's entrance. He pulled his key card through the scanner to open the Core's door, but access was denied. He tried again. Denied. Again. Denied. He'd have to override it.

Except he couldn't. They hadn't gotten that bug out of the system. Somewhere behind him he heard his name, but he _had_ to get inside. There had to be a way.

He had to make sure his ducklings made it out.

After every manner of attempted override, he let out a grunt of frustration and summoned a bone. It crashed through the console, and the door opened.

There was no time to lose.

He ran inside, calling Erie and the interns by name. Even _he_ could tell it was hot; if anyone was in here, they would be roasting. Maybe they had left. Maybe they all went home.

He couldn't bring himself to even pretend to believe that.

He ran through the corridors and work rooms. God, where _were_ they? How deep had they been working? He hadn't even looked.

He let out a cry as a plate shot up right in front of him, scalding steam nearly boiling the marrow right in his bones. Once it subsided, he jumped over the gap and ran forward.

There they were.

A large window looked into the main room of the Waterfall wing. A few monsters in there were sagged on the floor; still alive, but only just. Erie and a few other reptilian monsters banged on the window, but it did no good; they'd made sure to get shatterproof glass.

"I am here, I am here!" Gaster called as he ran in. Erie's eyes widened, and she pressed her claws against the glass.

"The emergency lockdown system's broken! The door won't open and I can't override it!" she yelled, voice muffled by the window and nearly drowned out by the alarms.

"I know, I know! But…but I will get you out!" Gaster shouted back. He went to the console, immediately pushing every button and twisting knobs. The alarm was deafening, and the banging on the window seemed to slam right into his skull, but he kept his focus on the controls. He had to get them out. They would survive.

 _He would make sure they survived._

But nothing was working. Even an attempt to break the machine with an attack only lead to bones bouncing onto the floor. He slammed a fist against the console before grabbing two levers designed for manually opening the door. He pulled hard at them. He knew they were locked, but if he was just a _little bit stronger…_

The banging grew quieter. Gaster looked up with wide sockets, still fighting with the levers, and Erie stared back with dull eyes as her arms went slack. She knew what was going to happen. So did he.

There was a moment of terrible stillness.

And then it happened.

* * *

Gaster would never remember much of the Core's explosion. Just an immeasurable force throwing him back, a blast of heat, and blinding pain as the controls tore through his hands. After that, all he knew was darkness and silence.


	11. Aftermath

Really, the healers said, he'd been quite lucky.

He'd ended up with several broken bones, but with a little healing magic, they had mended up like nothing had happened. He'd be sore, they warned, but only for a bit.

But then, of course, there was the issue of his hands.

The levers had gone straight through them, ripping out his capitates and a good chunk of metacarpals from each hand. With no bones to fuse back to, his hands couldn't heal the same as his ribs and legs, and it seemed there was no quick-fix for exposed marrow—at least, none that they knew. So they had no choice but to bandage his hands and let his body's magic heal the wounds. They'd take the bandages off in a few weeks.

With that, he was escorted from the hospital and dropped off at the big house in Snowdin, which was technically his, and he was too woozy from the blast and potions and being overloaded with magic to mention that he hadn't moved in yet. But he was in no state to walk back to Home, so he went inside.

And he stayed inside.

A week later, rumors started to rise. The Royal Scientist must have died from his wounds. Or maybe he hadn't actually made it out. Maybe he fell into his creation with the others.

As the monsters started to whisper, the Dreemurs decided it was time to intervene.

* * *

The knock echoed through the empty house. Gaster, slumped against a wall, groaned and covered his sockets with his bandaged hands.

"I _said_ I do not want to talk, Asgore!" he snapped.

"Well, _I_ would like to."

Gaster let his hand fall as he looked up curiously. That wasn't Asgore's baritone. "Toriel?"

"Will you please come out, my friend?"

Gaster scowled. "If I did not come out for Asgore, why would I come out for you?" He covered his face. "Just…leave me alone."

Toriel let out a huff on the other side. "It has been a _week_ since you've been released, and I doubt you had enough food to last that long. Surely you must be hungry."

Gaster scowled again, this time looking at the bandages on his hands. "I am not like you. I do not get hungry."

Well, that was a lie, but it wasn't like he would be able to eat anyway.

Toriel was silent for a long moment. Gaster drew his knees to his chest like a child, praying for her to leave.

"Gaster, it was an accident."

Gaster grimaced and shook his head. Wrong. Wrong, wrong, _wrong!_ He buried his face into his bony knees.

"How many?" he finally asked.

"What?"

" _How many?_ "

Another silence. "Seven."

The number pierced straight into Gaster's soul. _Seven._ Six interns—he could name them all, no doubt. One bright, organized assistant. God, he _should_ have fired Erie. He should have let her go home, should have let them _all_ go home. If he hadn't been so cruel and full of himse—

"Gaster, I am coming in."

He stayed silent, curling in as tightly as he could despite his height. He kept his skull knelt against his knees. The door creaked open, and Toriel let out a little gasp.

"Where are your things?"

"Home."

"So you have had nothing?"

He shrugged. "What would the point have been?"

Toriel walked over. He shut his sockets as he listened to her footsteps, and didn't move as she sat beside him. This was the last thing he needed. A small part of him wanted to blame her for what happened, but that was unfair. It was his emotions that led things to get to this point.

"Gaster, this was an accident."

He drew in tighter, willing her to leave.

"You cannot blame yourse—"

"The vents were not working, Toriel!" he cried out, head finally shooting up. "But I told them not to fix it! The safety system had malfunctioned for weeks, but I pushed it aside! The Core overheated because of me, and _seven monsters died_ because of my stupid decision to move up Waterfall's deadline!" He shook his head with a ragged gasp. "This is _my_ fault, and all that happens to me is _this_?" he asked, holding up his hands. "Where…where is the justice in this?!"

Toriel touched his arm. He looked up with another shaking breath. Her eyes glistened.

"There is no justice in tragedy, my friend," she said softly. "Do you think I have forgotten the monsters who died when we first came down here? Do you think I do not ask myself everyday how I could have helped save them?" She blinked, and two tears spilled over and streaked her fur. She swallowed as she squeezed his arm. "It will always hurt. You will never forget, and you will always think of what you could have done to save them." She swallowed hard. "But you _cannot_ let yourself stay in those thoughts."

Gaster blinked as he felt his own sockets grow wet. All at once, Toriel's arms were around him in a tight hug, one that aimed to comfort while begging for comfort in return.

"We must press on, with the living," she whispered against his shoulder. "Because in the end, that is all we can do, Wing Ding."

Slowly, carefully due to his bandaged hands, Gaster returned the hug. A sob escaped her as he did, and, for the first time in at least a century, he let one out as well.

They clung to each other like children as they mourned—for the interns, for the monsters lost in the war, for the parts of themselves that they lost with the victims.

Soon, it would be time to press on. But not now, not yet.

Even queens and scientists need time to cry.

* * *

A team of movers came in the next day. Gaster was nowhere near recovered, but he quietly let the movers put things wherever they saw fit. As they went in and out, a small bunny in a striped shirt darted inside the house, announcing that he had a message from the king and queen.

"They're having a…um, a thing about the explosion," the bunny said, scratching his ear. "And if you're feeling up to it, they said they'd like it if you'd come."

Gaster looked listlessly at the boy, and he sighed.

"Yes, I will come. It is only right," he said quietly. "They…er, they did not say that I need to… speak, did they?"

The bunny laughed. "Don't see why they would. You never talk anyway. But I'll run back and tell them." He paused in the doorway. "Um…I heard you got really hurt. Maybe you can take the ferry instead of walking."

Gaster's browbone furrowed. "Ferry?"

"Yeah! It's been in for the past few months. You can get all the way to Hotland in like a minute!" The bunny smiled. "Bye, Dr. Gaster!"

Gaster sighed and waved a bandaged hand. He supposed he ought to clean up.

* * *

Not too much later, in his black sweater, black slacks, and black coat, he asked around Snowdin as to where to find a ferry. Finally, he found the little opening between the trees just outside the town. A large river ran through, and floating serenely near the bank was a little boat and a cloaked person. Something about them seemed very familiar.

"Hello, I'm the riverman. Or am I the riverwoman? It doesn't…" The cloaked head turned to look at him, and they abruptly froze. After a moment, they asked, with a sudden coldness, "Where would you like to go?"

Gaster blinked. "Have we…" He raised his hands, but there was no way to sign with the way they were bandaged. "Er, can you go to New Home?"

"Just to Hotland," the riverperson said shortly. They raised a sleeve; perhaps they were just a sentient cloak. "Hop in."

Gaster stepped into the boat, and it almost immediately took off, nearly jolting him into the river. Once he steadied himself, he sighed and watched the Underground go by. The next few hours would be hard. But he just had to sit and look imp—

"Tra la la. Must be hard to speak with so much blood on your hands."

Abruptly, Gaster looked up. "What?"

"Tra la la."

"What did you say?"

The hood turned slightly. "I sing while I ride in my boat. Tra la la."

Gaster's hands tried to clench into fists, but the initial twitch had him grimacing. "I…I do _not_ have blood on my hands."

"Tra la la."

"I _do not!_ "

"Tra la la."

Gaster lunged forward, making the boat rock, but stopped himself and took several deep breaths. The riverperson didn't even flinch.

They couldn't know what had happened. No one knew, not even Toriel or Asgore. Had word gotten around from the survivors?

And why _blood_? Monsters didn't bleed. He shook his skull.

"Stop the boat," he said gruffly.

"What?"

" _Stop_ the _boat._ "

The riverperson was silent for a moment, but they stopped it just outside of Waterfall. Gaster quickly got out.

Once he was on land, the hood once again turned to look at him. "Beware the man who speaks in hands, Dr. Gaster," they said. "I hear he _likes_ to fight."

Gaster stared at them; they looked serenely ahead. Were…they there after the battle? After he had...but those were _humans_. And the Core was a different situation. And…

Gaster stood up straight and turned, walking away as quickly as he could. He took great care not to look back. Even so, he couldn't stop the riverperson's words rattling in his skull.

 _Beware the man who speaks in hands._

It…must just be the ravings of a sentient cloak. That was all.

* * *

"And it is with heavy hearts that we speak today. As you all know, the explosion at the Core has not only brought a halt to our progress, but to several young lives…"

Gaster, at his usual spot on the balcony, stared straight ahead as Asgore's somber speech went on. For once, Toriel didn't try to make him laugh. Even if she had, there was no way he would have even registered her. His thoughts were far off.

This was all his fault.

He had to do something. _Anything._ Just to even slightly ease the ache of guilt filling his center. He took a breath as he had an idea.

He took a few steps forward, which was enough of a shock to send murmurs through the monsters below. Asgore turned around, and he stared at Gaster curiously. Gaster swallowed.

"I…I want…" He cleared his throat, then gestured to the podium. "If…I may?"

"Oh, Gaster, you don't have to," Asgore whispered. Gaster set his jaw and stood up straight.

"Yes. I do." He looked at Asgore pleadingly, willing himself to hold his composure. "Please, Asgore. I need to."

Asgore looked at him for a moment, then nodded and stepped away. Gaster took a breath, then stepped forward.

Oh, _god._

There were so many monsters out there, and all eyes were on him.

He almost backed out right there. He couldn't speak! He couldn't subject them all to his hideous voice! He was meant to be in the shadows, working on progress in near silence. His fingers started to flutter nervously, but the quick stab of pain in his palms reminded him why he was here in the first place.

So Dr. W.D. Gaster took a deep breath, set his shoulders, and stepped up to the podium.

"I…" God, he didn't even have his hands to help him. "I…I cannot give you the hope King Asgore does. N-nor can I give you the wisdom of Queen Toriel. Truthfully, I…I am not able to give much of anything that usually comes in speeches. But, but of the little that I can give, the most relevant are the facts.

"The fact is the Core overheated and exploded. The fact is that we lost seven of the Underground's brightest young minds: Tryce, Marsel, Levaret, Bindy, Melusine, Ches, and…and Erie. The fact is that you, and I, and all of us here are mourning the loss of these monsters, of progress, of hope."

He swallowed as he looked out at the silent crowd of monsters. "But the facts do not end there. While I am hesitant to return to work, the fact is that we need power. While the explosion is still v-very fresh in my mind, the fact is that the Core is fixable. And, while I, like you, am deep in mourning, the fact is that those monsters would not want us to stop work on the Core. Not after they worked so hard. Rather, we must, we _must_ press on for the needs of the living rather than live in the regret of lives lost." He fell silent as his voice broke. Silence filled the Underground. He looked out the monsters, the living, and took one last, deep breath.

"Please, do not forget what has happened. Do not let the monsters who died be left in anonymity. But look forward. Look to where we are going, not where we have been. There, we will be able to find the progress we need."

He pulled away from the mic and walked back toward the balcony's exit. He heard claps and cheers and words, but he filtered them out. Really, it was only the clap on the shoulder that brought him back.

"Gaster," Asgore said. "That was…I mean, you, that was… _Listen_ to them!"

Gaster's face remained impassive. "I am glad they liked it, considering it was a speech for myself." He looked up wearily at Asgore. "I have work to do, Asgore. I must go."

Asgore looked over him, brows drawn in concern. But, after a moment, he nodded and let go. "Of course."

Gaster drew away, but stopped before he left. He didn't turn around. "Asgore?"

"Yes, Gaster?"

"Please, tell the University to not send any more interns." Gaster let out a breath. "I work best on my own."

Before Asgore could respond, he left. He walked as quickly as he could through New Home, hoping to avoid any and all interaction between here and the remains of the Core. He didn't know how long he could keep up his composure, and the last thing he needed was someone…

"Gaster!"

He stopped. Because of course he would. He turned, dully watching her gathering her black skirt as she ran after him. Toriel was immediately reaching a hand out for him as she drew closer.

"Gaster, I know how hard that must have been for you," she said before he could stop her. "And you were amazing in spite of the circumstances. And I…" She trailed off as he held up a bandaged hand.

"Toriel. Now is not…" He let out a breath. "Please, go back to your husband. He will need you once the questions begin."

Toriel's brows drew together. "And you need someone as well."

"I do not. I work best alone."

She looked up ahead, toward where he was headed. "You're going back to the Core?"

"I need to."

"But…but with what happened, surely you cannot…"

"We need power, Toriel," he said softly. "And I…I would like to be alone to work."

"But you need—"

He shook his head, cutting her off. "I need time to _heal_." He let out a breath as he met her eyes sadly. "More than just my hands. So _please._ Go back to Asgore and let me be alone."

It clicked. He saw it on her face. He wouldn't be surprised if she had realized that she, in a roundabout way, was the catalyst to all of this tragedy. She was clever that way. After a moment, she nodded, clasping her hands in front of her.

"Of course, my friend," she said softly. "But…be careful, please. The Underground needs the Royal Scientist."

Gaster gave a quick nod, then turned and walked away without so much as a goodbye. There was no time for that.

There was work to be done.


	12. Announcement

In Snowdin, two monsters sat watching their children, steaming mugs warming their paws. From inside their houses, next door to each other, electric light filtered out from the windows, reflected on the snowy ground.

"Did you hear? They're activating the last of the Core tonight," one of them, a bunny monster, said.

"Really? It—Jordie! I said stop tackling your brother!—So it's finally done." Her friend, a mouse-like monster, took a sip of her tea. "It's about time. Seems like they've been working on it forever."

"Well, that explosion threw everyone for a loop. Work must've shut down for five years after that."

"Explosion?"

"Did you never hear about that? Goodness, I'm showing my age. Oh, Nellie, honey, please don't use your sleeve to wipe your nose!" The bunny lowered her voice. "Anyway, I barely remember it myself; I was just in striped shirts. Anyway, there was a _huge_ explosion about halfway through the Core being built."

"Goodness sakes! Was anyone hurt?"

"I _think_ a couple of workers might have died? I know there's a plaque somewhere in the Core." The bunny shook her head. "For ages, the only place with power was New Home. I never thought they'd even go so far as to light the Ruins."

"Well, that Royal Scientist does like being thorough. Well, that's what I've heard, at least." The mouse sipped her drink. "Hey! Do you think he'll come out? I mean, this is a pretty big thing for him."

"Oh, he probably will. He's been working on this for almost fifty years. Why?"

"I just think he's _fascinating._ He's so mysterious, and he never speaks!"

"That's true, isn't it?" The bunny traced her mug. "You're right, he _is_ a mystery."

"Well, I'd better gather everyone if we're going to make it to New Home to see the speech. Thanks for the tea, Vill." The mouse stood up, then thought of something. "Speaking of the Royal Scientist, isn't it funny how he always wears black?"

* * *

It was remarkable how quickly a century could pass.

The Core had been fully operation for quite some time now—it had taken twenty more years than anticipated, yes, but considering it was more or less completed by just himself, that wasn't too bad. But this time there were no explosions, no casualties, and after the rounds of congratulations had been completed, Gaster was free to retreat to the lab and enjoy his solitude.

Oh, certainly, the Dreemurrs coaxed him out every now and again—he and Toriel had…well, not _reconciled_ , per se, but the worst of the awkwardness between them was gone and things were pleasant. There was also the obligatory attendance for royal engagements and speeches, but less now than there had been a century ago; since the accident, Asgore hadn't insisted he come nearly so much.

For the most part, though, he stayed in his lab, trying to find things to do. He updated the New Home section of the Core, which it needed after a century. He came up with better pipes and security systems. As of right now, he was writing a textbook on magic and physics in the Underground (though it would definitely need an editor.)

While there were still things to be done as the Royal Scientist, he couldn't help but feel a bit empty now that his work on the Core was over. After all, he'd spent nearly half his life working on it, and since it was complete, there was no more planning to be done. He had _time_. And quite frankly, he didn't know what to do with it.

So, most days, long after the workers had gone home, he went to visit his creation. He would climb to the very top level, where he could look out at all the machinery, all the perfectly-working pieces that now gave power to the Underground.

He had done what he set out to do. He'd tamed the roiling pool of molten earth. He had _proven_ that his mind could overcome nature's forces. He had—

Whenever these thoughts came, he found one hand drifting to the hole in the other, lightly rubbing the mangled bones. While there were now more chips and nicks on his hands to go with these scars, the holes were still strange, still jagged a century later.

They still served as a reminder of what his pride had done.

Usually, at that point, he would retreat to the lab.

It was a quiet life he led now, a somewhat regretful one, truth be told. But the solitude suited him. If he was alone with his thoughts, he could sort them rather than shoving them down for the sake of keeping up appearances. And so, very slowly, he started to think about forgiving himself.

This lifestyle came to an end before he could get to the actual _forgiving_ part, though.

* * *

It started with the lab doors opening unannounced.

After spending so long on his own, he had been genuinely startled by the intrusion. He barely managed to grab the mug of tea he'd nearly knocked over, saving his notes for the textbook from a wave of tea.

"Er, civilians are not allowed…!" he started to call out, but stopped as he heard a quiet laugh. He relaxed as he recognized it. "Well, I suppose the queen does not require any clearance."

Toriel gave a small smile at the old joke as she walked in. "I did not mean to startle you."

"You know, you have said that for nearly two hundred years now, and yet you always startle me." Gaster motioned to one of the stools as he gathered his notes. "Please, sit. I just need to, er, move a few things."

Toriel settled herself on the stool, sitting very straight. Gaster glanced at her, catching her bright eyes and twiddling thumbs. She somehow looked hesitant and excited all at once. He set his papers down and held up his mug.

"Tea?"

"No, thank you. I cannot stay for long."

A peculiar pang hit the inside of Gaster's ribs at the polite refusal, but he ignored it. Things were better now; no sense letting nostalgia make things awkward again. He leaned against one of the counters and sipped his tea.

"So then, we best, er, get to business, I think is the term."

Toriel nodded, looking down as she began fiddling with a pen. The hesitance had clouded over her excitement, it seemed. Finally, she took a deep breath. "Well…there will be an important announcement soon."

"Of course I will attend," Gaster answered with a wave of his hand. Toriel shook her head with a small laugh.

"That is not what I came here to tell you. Well, I mean, I would still like it if you attended, but…" She let out another quick laugh, patting one of her ears. "I-I did not think this would be so difficult to discuss with you."

Gaster frowned. "Is there something wrong with the Core?"

"No."

"Do they want me to give a guest lecture at the University again?"

"Goodness, no."

Gaster snapped his fingers. "You are replacing me. My days as Royal Scientist are over."

"Do not be ridiculous, Gaster!" Toriel chided. He shrugged.

"Then I do not know what it is that is so difficult for you to tell me."

She sighed. "It is…well, it does not concern you specifically. But…since you are Asgore and my dearest friend, it only seemed fair to tell you. But…I know you have been concerned about it in the past…"

He frowned. "It does not concern me, but it concerns me?" He shook his head. "You know better than to tease a non-native speaker with riddles, Toriel."

Toriel smiled at him, then took a deep breath. She met his sockets.

"Asgore and I are having a child."

His mug froze halfway to his mouth.

A child _._

 _Now?_

Oh, he'd always known they'd have one eventually. They both took care to meet all the children that came to events. They cooed over the particularly cute ones. And they would both be excellent parents. Their child would no doubt be a delight, regardless of which parent they took after.

But Toriel and Asgore would _die._

How long did they have left? Monsters generally matured by twenty; were two measly decades all he would have until they dissolved? And how often would they be able to talk to him once they were taking care of a child? This was a death sentence for them and unspeakable loneliness for him.

He set down his mug.

"Gaster…" Toriel got to her feet and immediately reached out to him, just like she used to. She stopped, though, as he took one of her paws in his mangled hands. He gave her a warm, wide smile.

"Congratulations." He meant it, surprisingly enough.

Toriel gave him a surprised look, and he patted her paw.

"I know you and Asgore will be astounding parents."

Toriel looked at him for a moment longer, then let out a long breath as she returned his smile with her own bright one. She squeezed his hand. "I am so glad you understand, my friend."

He smiled as he drew his hands away. Of course he understood.

Because, really, what else could he do?

* * *

And so, the next day, Asgore made the joyous proclamation that he and Toriel were expecting. And, several months later, they were both in front of the Underground again, this time to present Prince Asriel to the public.

The whole Underground was thrilled, of course. Nothing boosts morale like a royal baby.

Meanwhile, very quietly, Dr. W.D. Gaster turned back to his work. The countdown had begun.

Very soon, he would be alone again.

* * *

 **End Part 2.**


	13. Arrival

**Part 3: The Human**

* * *

Despite everything, it was actually _very_ hard to resent Asriel. As he grew, he proved to be an incredibly charming child. Yes, he represented the end of their new normal Underground; yes, he would be the source of his parents' demise when he was grown. But he had so much of Asgore's friendliness and humility—it seemed like he only knew he was the prince when forced to stand through _very_ important ceremonies, and even then, he would sometimes sneak away halfway through to play with his friends.

That's not to say there wasn't a good deal of Toriel in him, though. He was inquisitive; by age 8, he'd traipsed through most of the Underground to satiate his endless curiosity. And, on the rare occasion Gaster was put on "babysitting" duty, Asriel would spend nearly the entire time asking questions about the Lab and the Core.

Gaster…wasn't keen on children, no. But he found that he didn't mind Asriel at all.

But, really, the troubling part was never Asriel himself. It was Toriel and Asgore. Gaster wasn't prepared for how _quickly_ Toriel and Asgore would age. In less than ten years, they were solidly middle-aged. But, still basking in the glow of parenthood, neither of the Dreemurrs were bothered. Toriel laughingly noted that she would need reading glasses soon; Asgore poked fun at the fact that his mane of blond hair had begun to recede.

They settled comfortably into this phase of life, apparently at ease with the fact that their time was running out.

Gaster was horrified.

But, in spite of that, he said nothing. Because really, what could he say? The only thing that would stop this would be Asriel's death. And even on his most callous, bitter days, Gaster could never wish for that.

So, in a strange, forced way, he found peace with it as well.

* * *

This day started like any other. The door to the lab opened without any warning, but the soft footsteps immediately told Gaster who it was. He pushed himself away from his notes—the Core could do with some puzzle updates—and stood up.

"Ah! I will need some form of identification," he called to the intruder. He smiled as he heard the giggle.

"Dr. Gaster, it's _me!_ " Asriel set a package on one of the lab tables before pulling himself up into one of the chairs with a grin. Gaster shook his head as he walked over.

"I cannot trust that. What if you are an imposter?" Asriel laughed as Gaster glanced down at the neatly wrapped bundle. "What is this?"

"I can only tell you if you believe that I'm Asriel!"

Gaster smiled, then picked up the little package. "Well, if my hypothesis is correct, then this is a pie from Toriel. And, if that is the case, then you _must_ be Asriel." He looked down at the boy. "May I open it to verify?"

Asriel grinned and nodded. Gaster gave the string a quick tug, and he smiled as he caught a whiff of cinnamon.

"This is definitely one of your mother's pies, so you must be Asriel," he said, then bowed his head. "Forgive my doubt, your highness."

Asriel laughed before nodding back, ears flopping. "You're forgiven." As Gaster went to put the pie away, Asriel hopped down to follow him. "Mom said I have to make sure you eat it."

"She sent you all this way just to make sure I eat?"

"Well, and because she and Dad have some sort of meeting with some spiders."

"Ah, I see." Gaster set the box down and grabbed his lab coat. "Then I suppose it is time for an experiment."

Asriel's eyes lit up, but then he glanced over at the pie. "Um, well…shouldn't you eat first? Mom said I had to make sure you do."

Gaster smiled, then went to a cupboard and pulled out two (mostly clean, not-used-for-stirring-chemicals) spoons, like he always did when Asriel brought over one of Toriel's pies. "Well, then, I suppose I should." He smiled as he held a spoon out to Asriel. "But I will need some help."

Asriel gave Gaster a bright grin as he took the spoon. He pulled himself up into a chair as Gaster set the pie between them. After a few bites, though, his little brow furrowed. Gaster looked at the little boy curiously.

"Not fond of cinnamon?"

Asriel shook his head. "No, I…" He gave a little huff as he poked at the pie. "Can I ask you something?"

Gaster's browbone rose, and he set down his spoon. "Of course, Asriel."

"Why can't I have a little brother?"

Oh, god.

Gaster stared down at Asriel, unsure of what to say. Surely this was a talk for Toriel and Asgore to give him.

"Or a sister!" Asriel interjected. "I'm not really picky!"

Gaster tapped his fingers. _God._ This wasn't his area.

"Well…I…I think this is really something you should ask your parents about…" he said slowly. Asriel huffed.

"I _have._ But they just told me that they pour so much love into me that they can't have anymore," he said with a little pout.

Gaster relaxed slightly. Well, at least he had a general idea of what was happening. That saved both of them from a very awkward conversation. "Well, then, that is that."

"But I still _want_ one!" Asriel said, a slight whine creeping into his voice. "All my friends at school have brothers and sisters! It's boring just having Mom and Dad at home." He slouched with a little pout, then perked up as he looked up at Gaster. "Can you make me one?"

Gaster chuckled. "I am not that clever, Asriel."

"But you're the _Royal Scientist!_ So you must be the smartest!"

"Not smart enough to make brothers and sisters."

Asriel puffed out his cheeks as he plopped his chin into his hands. "Do you have any brothers or sisters?"

Gaster blinked, caught off-guard by the question. "I…erm, yes, I did." He shut the pie box, more for something to do than anything else. "I had two younger sisters."

"And isn't it better having little sisters?"

One thing Gaster was regularly surprised by was how Asriel asked very difficult questions without _realizing_ he was asking difficult questions. But he supposed that was part of being a child.

"I suppose." He twitched out a small smile. "Though Marlett would often spend far too long getting ready."

"That'd be fine. My little sister could take as long as she wanted. And I'd share my toys with a little brother!" Asriel sighed, then got down from the stool. "Can I go to the ruins?"

The ru— _ah,_ he meant Home. "I thought we would do an experiment."

Asriel was quiet for a moment, patting his ear absently. "I think I'd rather pick some flowers."

"Should I go with you?"

"Nah, I go all the time by myself."

Gaster looked at the little prince dubiously. "If I let you go, will your parents be angry with me?"

Asriel smiled. "Don't worry, Dr. Gaster. I'll take the blame." He shrugged. "I mean, I'm just a kid. How mad can they get?"

Gaster weighed this for a moment. He probably _should_ go with him…but really, the Underground was tremendously safe. How much trouble could Asriel get into? Besides, he really did want to finish the puzzle schematics by tonight. He smiled.

"Then we will save our experiment for another time. Have fun, Asriel."

The boy grinned. "Thanks, Dr. Gaster! And thanks for sharing the pie!"

He ran out of the lab, and Gaster smiled after him before returning to his worktable. He sat quietly for a long moment, staring down at his notes without actually reading them.

Well.

It'd been quite some time since he last thought of his sisters. But…Asriel did have a point. He supposed, all things considered, it was better that he had them, even if it wasn't for very long. Strange how a child could make him think so much.

He let out a breath and pushed aside his nostalgia. He could dwell on this later. For now, it was time to work.

* * *

He got the news that evening.

Asriel had found a _human_ in the ruins. A living one.

Gaster wasted no time running to New Home, kicking himself the entire way. He hadn't thought about the possibility of a human falling down. He should have gone with him. He should have kept him at the lab. God, if anything happened to the little boy…

He rapped his knuckles on the door hard enough to hurt. God, _god,_ let him be okay…

He let out a long breath as Asriel opened the door. Oh, thank _god._

"Are you all right?" he asked quickly. "You are not injured or…?"

Asriel laughed. "Golly, Dr. Gaster, that's a silly question." He grinned up at the scientist. "Did you come to meet them?"

Gaster blinked. "What?"

"Did you come to meet Chara?" Asriel took one of Gaster's mangled hands and pulled him into the house. "Mom and Dad were gonna call you once they were sure Chara was all right. They got kinda hurt from falling down so far, but Mom thinks they'll be okay in a few days."

Gaster stayed silent, trying to process all of this. Was Chara…no, they couldn't be the human. Asgore and Toriel wouldn't be that stupid. They wouldn't…

Asriel guided him to his room. Toriel was crouched at the bed, humming gently as she worked her healing magic. She shifted to look at him with a smile.

 _No._

In the bed, in _Asriel's_ bed, there _it_ was. A human. It wasn't much bigger than Asriel—clearly a child. But that didn't make it any less dangerous. It looked as though it were asleep…what would it do when it woke up? If it was scared, it could get violent. And in the home of the monsters' royalty…

He looked down at Toriel, sockets dark. "A word, your majesty," he said through his teeth.

Toriel blinked, then frowned. "Can we not speak here?"

" _No._ "

Asriel glanced between the two grown-ups. "Don't worry, Mom! I'll stay with Chara!"

Toriel glanced down at her son, then let out a sigh as she got to her feet. She met Gaster's gaze with steely eyes as she swept out to the hall. Once they were in the living room, Gaster's hands were everywhere as an explosion of thoughts came out. After some effort, he could only vocalize two words.

"A _human?"_

Toriel's gaze remained icy. "Yes."

Gaster stared at her. "Does Asgore—"

"Yes, he knows. He is out buying the poor thing some clothes; Asriel's are too small."

"Buying some…for _God's sake, Toriel!_ Have you forgotten why we are down here? Have you forgotten _whose fault_ it is that your race is decimated and mine is practically extinct?"

"I have not."

"Then why would you have that…that _creature_ in your house?"

"Do not refer to them as a 'creature', Dr. Gaster," Toriel said coldly.

"Toriel, you have a _child!_ How you do not see the danger—"

"And now I have two."

Gaster went silent, a chill creeping down his spine. " _What?_ "

Toriel drew herself up, looking as cold and queenly as Gaster had ever seen her. "Asgore and I have decided that we will raise Chara as one of our own. They can be a symbol of peace."

Gaster snorted. "To who? I am certain we are nothing but fairy tales to the humans now." He stood up straight, meeting Toriel's gaze. "There is only _one_ way to deal with a human. You know what that is."

Toriel's eyes narrowed. "Perhaps this is _alien_ to you, Dr. Gaster, but monsters do not fight unprovoked. Chara is a _child_ , and they will be treated _just like Asriel._ " Gaster opened his mouth to argue, but Toriel took a swift step toward him and added, in a low, dangerous voice, "And if I _ever_ get word that you have harmed one hair on my child's head, then there will be hell to pay, Wing Ding."

Gaster glared back at her, sucking in deep breaths. His hands spat out ugly phrases.

 _You and Asgore are being idiots. This child will doom us. You are both putting YOUR CHILD in grave danger._

He finished off with the worst thought on his mind.

 _The only way we will be safe is if we kill it now._

He let out one last breath, then bowed his head stiffly.

"Very well, your highness," was all he said. With that, he turned and started to walk out. He stopped, though, as he saw a dark eye peeking out from behind Asriel's door. The door quickly closed.

Another chill went down Gaster's spine. There was nothing good about this human child.

* * *

Initially, he'd refused to attend the ceremony officially recognizing Chara as a member of the Dreemurr family. But the request turned into a demand, and that changed things quite a bit. So, very grudgingly, there he was, in front of everyone and pretending to approve of having a human Underground.

And, naturally, Chara, still pale and looking a bit weak, was there as well. They sat very still in their chair, dark eyes wide, as if they were frozen in place. No doubt they weren't used to so much fuss; humans, he was certain, didn't raise the same fanfare over everything that monsters did. Asriel held their hand and whispered to them the entire time, but it seemed to do little to reassure them.

Gaster might have been sympathetic, except…well, for obvious reasons. So he stood in place, waiting for the ceremony to be over. It wouldn't send Chara away, but he'd be able to pretend his friends weren't as stupid and reckless as they were.

It did, mercifully, come to a quick end, and Gaster was on his way out in record time. However, before he got very far, he felt a quick little tug on his coat. He frowned a bit; it wasn't often he was greeted that way. He turned.

A pair of dark eyes were staring up at him.

"Dr. Gaster?"

Gaster sucked in a breath as he looked down at the human. "Chara."

The human stared for another moment, then gave him a smile. "It's nice to meet you. Asriel's told me about you."

"Has he?" God, he wanted to leave. The less time spent talking to a human, the better. His browbone furrowed as Chara lifted a hand.

"I hope we can be friends, too. Like you are with him."

Gaster could barely hide his revulsion as he reached out to give Chara's hand a quick pat. "Well, we will see."

He said this lightly, but the flash in Chara's eyes told him they caught the sincerity. They smiled wider.

"We will. But I ought to go find Asriel. Goodbye, Dr. Gaster!" they said, then quickly ran back toward the Dreemurrs.

Gaster stared after them, then shook his head as he turned to head back to the lab. That human would be dangerous.

He was certain of that.


	14. Different

_It has to be SOMEWHERE_ _in here,_ Gaster signed absently with one hand as he flipped through his dictionary with the other. He had the _perfect_ phrase to be used in the textbook, but _confound it_ , even with nearly two hundred years of speaking Monster, he could _not_ translate the stupid thing. And he wagered that the future students reading the text wouldn't appreciate a string of random symbols.

He shut the dictionary with a huff before getting to his feet. _Forget it_ , he signed to himself. _I'll rewrite it later._

A little giggle came from the other side of the lab. He blinked.

"Hello?"

No answer. He glanced down at his hands, then half-smiled. He shrugged before signing, _I guess it's just my imagination._ He heard another little giggle, then smiled as he began to sign the first few lines of "The Femur's March".

"Woah!"

"I _told_ you he did this when no one looks."

"Golly, I never even knew…"

"Yeah, he does it all the time when he talks to Mom about us."

Ah, so he _did_ have visitors. Quietly, he walked over to the table where the voices were coming from. Abruptly, he leaned down to look at the two intruders.

"Who does what when he speaks to your mother?"

"Ah!" Asriel fell back in surprise, then let out a loud laugh. "Dr. Gaster, you scared me!"

He smiled. "My apologies, Asriel," he said as he crouched down.

"You didn't scare me."

Gaster's gaze went to the other child. Chara smiled back at him, dark eyes glinting. He let out a breath.

"Yes, well, I suppose it would take more than that to scare you, Chara." He stood up, watching the two as they crawled out from under the table. "Did your parents send you here?"

"No, Chara just wanted to show me your hand thing," Asriel said, dusting off his striped shirt. "I didn't believe them."

"That's because you don't pay attention to things," Chara said matter-of-factly as they pulled themself up onto a stool.

"I do, too!"

Chara laughed. "Okay, _sure,_ Asriel."

It really was quite remarkable how much of a difference six months made with the human. Anyone who met the rosy-cheeked, smiling child here would never guess that they were the same pale, quiet child that had fallen down into the ruins. They were friendly enough to everyone, and obviously adored Asriel, but even so…Gaster couldn't trust them. They weren't proving themself to be like other humans, but something about their eyes…

"So is your hand thing why your hands are like that?" Asriel asked abruptly, pulling Gaster out of his thoughts.

"Er…well…no," he said, automatically rubbing one of the jagged holes with his thumb. "It is from an…er, accident. Since you two are here, we should try—"

"Was it from when the Core blew up?" Chara asked quietly.

Gaster's back went ramrod straight, and he looked down at the child with wide sockets. "How did you—?"

"It _blew up?_ " Asriel exclaimed, then puffed and gave his adopted sibling a little shove. "You're lying, Chara! I'd know if it blew up."

"It _did_ ," Chara insisted. "There's a plaque at the entrance!"

"I've never seen it!"

"Because you don't _look!_ "

As they bickered playfully, Gaster relaxed. Of course. He'd forgotten about the plaque. And really, it was silly of him to think Chara would just _know._

"Chara is right," he said once he recovered from his shock. "But that was quite a long time ago, and I am sure you will hear more about it in school." He clapped his mangled hands together, putting on a smile. "And besides, there are much more interesting things to do. Asriel, your mother tells me that you are starting to play with magic."

Asriel made a face and scratched his ear. "Not really. Not like Mom and Dad."

"He can make his hands smoke," Chara said with a smile. "It's kinda cool."

"It's not that cool!"

Gaster chuckled as he pulled over a stool to sit across from the two children. "Soon enough, you will be lighting the stove. Let us see if we can nudge you a little closer to that point."

Both Asriel and Chara looked up with bright eyes. "We're gonna practice _magic_?" Asriel squeaked out.

"Well, the laboratory is the safest area in the Underground. I see no better opportunity than the present," Gaster said as he sat down. He tapped his fingertips together as he looked at the two children. "Now, one thing you will need to keep in mind is that, while you are still growing and getting used to your magic, you may find that it responds well to strong thoughts or emotions." He chuckled. "But be careful. I broke my mother's favorite vase during a particularly bad fight with my sister."

Asriel smiled and pulled Chara into a hug. "That won't happen. Chara and I never have _real_ fights."

Chara smiled at Asriel, but then looked to Gaster with a frown. "You can't do magic, though."

Gaster blinked. "Why not?"

"Because you're a scientist. Scientists don't believe in magic."

Gaster half-smiled. "Ah. Well, I am afraid that is not true. With Monsters, magic and science are intertwined. With the amount of magic down here, as well as our biology, it needs to be."

"Prove it," Chara said, meeting his sockets defiantly.

His browbone rose, but he shrugged. "Very well. I suppose I brought the burden of proof on myself." He turned slightly to look at an empty corner of the lab, then flicked up his hand. Immediately, several bones shot up from the ground, just barely missing a lamp overhead. He swiped his hand quickly to dismiss the attack, then turned back to the children. "Is that proof enough?"

Both were silent, looking up at him with wide eyes. Asriel immediately sat up straight.

"I wanna try!"

Gaster smiled. "All right. First, hold out your hand."

Asriel did so, looking at his paw with laser focus.

"Now, focus on your Soul."

Asriel shut his eyes tightly and nodded. Chara looked at him for a moment, then did the same.

"Now, do you feel it…er…that…erm…" Oh, god, what was the _word_?

Asriel scrunched his nose. "It feels like my Soul's kinda getting bigger."

"Yes, good! That is what you want! Now, push that feeling out of your chest and to your hand…"

Asriel screwed up his face, clearly focusing. After a moment, a little white pellet appeared above his hand, spinning in a lazy circle. Gaster clapped.

"It worked, Asriel! You did it! Look!"

Asriel opened his eyes with a bright grin. "I did?" He looked down at his hand, then frowned at the little pellet. "Oh, that's _lame._ I thought I'd have fire."

Gaster chuckled. "It will come in time, Asriel. Now, since you are ab—"

"It's not _working!_ "

Both Gaster and Asriel looked up at Chara's outburst. They stared hard at their hand, then shut their eyes and grimaced, fingers twitching. After a moment, the hand clenched into a fist.

"It's not working," they repeated angrily. "The instructions must be wrong!"

Gaster tapped his fingertips together. _Ah._ Well…that was interesting, but, when he thought about it, not all that surprising.

"Well…in my experience, humans are not able to use magic the same way we are," he explained. "Our bodies are comprised of mostly magic, while humans…"

"That's _stupid_ ," Chara snapped. Asriel quickly wrapped an arm around them.

"No, no! It's fine, Chara. Look, I won't use my magic, that much, so we—"

Chara let out an irritated noise as crossed their arms. "No. You should use your magic."

"But Cha—"

"I don't want your _pity_ , Asriel!" they snapped.

Asriel blinked. After a moment, his lips trembled slightly. Chara's eyes widened.

"Oh, Azzy, _don't._ "

Asriel rubbed his eyes. "I'm not crying!"

"You're a really bad liar." With a sigh, Chara reached back to rub Asriel's back as he sniffled. "Jeez, Asriel, it's not that bad."

This was all _entirely_ out of Gaster's comfort zone. He looked between the two, then let out a little breath. "Perhaps…now would be a good time for you to head back."

Chara looked up at him, then nodded. "Yeah, Mom's gonna be worried." They gave Asriel's back one last rub, then hopped down from the stool. Asriel followed. They both dutifully said their goodbyes, then left the lab.

Gaster tapped his fingers together as he thought. Well. He wasn't keen on Chara, but this _did_ seem like an interesting quirk to look into. A human's lack of magic, despite being in a place heavily saturated with magic, was surely something that could fit into his textbook.

* * *

"I feel as if I've completely abandoned you, my friend!"

Gaster kept his gaze on his teacup as Toriel filled it. After nearly a decade, he really should be used to the changes, but every time he visited, he was jarred by his friend's appearance. After all, the two hundreds were the prime of a monster's life, but here she was: soft and motherly, comfortable with the fact that old age was right around the corner. Really, how could he not be startled when his friend was somehow both his age and nearly old enough to be his mother?

He took a sip of tea to get out of his head, then smiled at her.

"You should not worry. I have been…er, well, I suppose I have never been good at…is the term 'reaching out'?

Toriel nodded with a smile as she filled her own cup. She sat down, settling back in her seat. "Well, I have the children, you have your textbook...who knew those would be such commitments?"

Gaster half-smiled and nodded before sipping his tea again. "Speaking of my book…" he said slowly, setting his cup down. "I would…like to ask you something."

"Of course, Gaster. How can I help?" She leaned forward with a smile, eyes bright and interested. There was an odd twist in Gaster's middle as he caught a glimpse of a much younger Toriel. He traced the top of his cup.

"Well…I have noticed something…curious with Chara. If you do not mind, I would like to look into why they are not able…"

"They are a late bloomer." Toriel's voice was flat and cold. He frowned.

"You know that is not true."

"It is a perfectly reasonable explanation," Toriel defended. "Asriel is a Boss Monster; both Asgore and I were more advanced than our peers and…" She trailed off as she met Gaster's skeptical look. She let out a quick huff. "We do not know for sure."

"Yes, we do, Toriel."

"Humans used magic! That is how the Barrier came to be!"

" _Wizards_ used magic. My knowledge on Mankind is not extensive, but I do know that they had to study for a very long time to _marginally_ use magic. Most humans, if you will recall, used weapons."

Toriel let out a breath, sinking back in her seat. "It will not be a problem for some time. Most monsters do not have a grasp on magic until they are fourteen, and perhaps by that point…"

Gaster stared as she spoke, and he abruptly waved a hand to stop her. "So you will lie to them?" She didn't answer. "That is _cruel,_ Toriel, even _I_ can see that."

"It is not! I know what I am doing, Gaster!" Toriel shot back. "Asgore and I have agreed that this is the best course of action."

"Oh, of course, the best course of action is to raise their hopes only to smash th—"

" _This is not your child, Wing Ding_ ," Toriel snapped.

Gaster drummed his fingers on the arm of his chair, staring hard at her. After a moment, he huffed out a breath. "No. I suppose they are not."

They fell into a silence, both taking their cups and sipping their tea without looking at the other. After a few moments, Gaster set down his empty cup. Toriel glanced down at it, then leaned over to refill it.

"You know," she murmured, "none of the new generation knows that you are not a monster."

He looked up at her. "And you think the same will happen with Chara."

Toriel refilled her own cup. "Yes. I do."

Gaster looked down at his cup, then slowly leaned over to take it. He watched the steam curl into the air. "It is possible, I suppose." He hesitated, then set the cup back down. "I really should get back to the lab. Thank you for the tea, Toriel."

As he got to his feet, Toriel quietly said, "We do not want to risk alienating them."

Gaster paused, but remained silent. He glanced back at Toriel, who fiddled with a teaspoon.

"They…it was not an accident that they fell down," she said with some difficulty. "Their life above ground was not…they decided to…" She covered her mouth, looking close to tears.

"They decided to…?" At Toriel's distraught look, he let out a soft, " _Oh_."

She let out a quick huff, shaking her head. "There was a reason they survived. They need to be _loved_ , Gaster. And we cannot do that by making them feel like they do not belong."

Gaster stood in the doorway for a moment, his hands half-forming a thought before he flexed them and dismissed it. It wasn't what Toriel needed to hear. He let out a long breath.

"Even so…give Chara the respect they deserve," he said. "They are clever. They will find out on their own if not from you." He glanced back at Toriel. "Thank you for the tea. I…had missed our talks."

Before she could respond, he was already heading to the door. As he left, he swore he saw dark eyes watch him leave.

* * *

Some months of peace followed the talk. While Gaster drew up some hypotheses on Chara's development in a magic-based environment and their lack of _any_ magical inclinations, he never translated them out of his language. It just wasn't worth the risk.

Not that there would be a chance for him to say anything. The last few visits to the Dreemurrs' house left him feeling muzzled; if the slightest mention of Chara not being a Monster was brought up, both Toriel and Asgore gave looks that reminded him that they _were_ , in fact, the strongest Monsters in the Underground. So, lately, he'd been politely declining, and spending his time in the quiet of the lab as he worked on his textbook. Or, in today's case, putting the final touches on some Core updates.

Naturally, then, when the doors slammed open with a bang, he nearly dissolved from surprise.

" _Are Mom and Dad gonna die?!"_

He blinked, alarmed at the shouting and stomps and crashes as chairs were shoved out of the way. He quickly got to his feet, only for a small mass to run right into his middle. He stumbled back, then looked down once he caught his balance.

"Chara?"

The child looked up at him with fierce eyes. "Are Mom and Dad gonna die?" they repeated.

"Er…not immediately, to the best of my knowledge."

"No! When Asriel grows up! Are they really gonna die?" they demanded.

Gaster blinked again, then rubbed his skull awkwardly.

"Er, I…I think this is a conversation you should have with your parents."

They shook their head violently. "No, it's gotta be you. You're the only one who'll tell me the truth."

"What?"

"Mom and Dad lie to me all the time! Even Asriel's starting to do that! You don't care if you hurt my feelings, so you can tell me!"

Gaster blinked, then sighed. He wasn't surprised; he _had_ warned Toriel about underestimating the child, after all. But _god,_ why did _he_ have to be the one they turned to?

He sat down on one of the stools, then motioned for Chara to sit. Once they climbed up and sat, he met their gaze seriously. "Yes. In order for Asriel to grow up, your mother and father will need to die."

"That's _stupid!_ "

"It is not. It is the way their biology works," Gaster said evenly. "I am sure there is a reason for it, even if it is not one we can understand." He clasped his hands together. "How old are you?"

"Why?"

"Just tell me."

"I'm almost eleven."

Gaster nodded. "So you will be close to twenty-one when they dissolve. That is plenty of time."

Chara frowned. "No, it's not! I need more!"

"You do not get more. Not unless Asriel dies."

Chara blinked, then frowned as they looked down at their hands. "I…I don't want that."

"I did not think so." He stood up. "Now, you should…" He trailed off as the lab's phone rang. He frowned; it wasn't often he got phone calls. He glanced at Chara, who seemed to be curling in on themselves. He frowned, then got up and answered it.

"Dr. Gaster speaking."

"I am so, _so_ sorry to bother you, Dr. Gaster," came a breathless voice on the other end. "We, I…uh…this is Miss Wyvern, from the school."

"Yes?"

"Well, um…well, you see, Chara's gone missing. And we're trying to contact everyone we can…"

Gaster looked over in alarm at Chara, who seemed to be trying to hide in their sweater. "Missing?"

"Yes, they just ran out of the classroom! We haven't contacted the King and Queen yet, but…well, I know you have monitoring equipment a-and…"

He furrowed his browbone at Chara. Over the collar of their striped sweater, their dark eyes were wide and pleading. He sighed.

"I am sorry, that is my fault. I meant to send a notice," he said.

"A…notice?"

"Yes. They are interested in my work on the Core, so I arranged to take them on a…field trip, I think, is the term. I forgot to send a note."

"Dr. Gaster, I don't really thi—"

"Is there a _problem,_ Miss Wyvern?" Gaster asked, using his most official, scientist-sounding tone.

"Er…no! No. I'll…I'll just let the staff know. Um…thank you, Dr. Gaster. Enjoy the field trip." The phone clicked and went dead. Gaster sighed as he hung up the receiver. Chara's face popped back out from under the sweater's collar.

"Did…did you just lie for me?"

"Yes, and do not expect it often," he said shortly, going back to his work desk and gathering his supplies.

"Why? You don't like me."

Gaster blinked. "I…Chara, I…"

"Don't lie," they said as they hopped down from the stool. "I can tell."

Gaster looked at them for a long moment, then let out a breath. "Well. I am not _petty_. Come here and hold out your arms."

Chara hesitated, but did as Gaster asked. "Why?" They'd barely gotten the word out before a mound of wires and tools were dropped into their arms.

"Because we are going on a field trip to the Core, and you may as well be useful."

* * *

There had been a strict rule about children not being allowed in the Core, so Chara was in silent, wide-eyed amazement for most of the time Gaster spent fixing up odds and ends. But after some time, they got bored enough to start asking questions. First it was just simple things about the Core, then some more advanced questions about magma and energy.

But then, as they climbed up to the Core's highest point, Chara hit him with a hard one.

"Do you ever feel… _weird_? About being with Monsters?"

He stopped as they reached the top of the catwalk. "Do I…I-I do not understand."

"I'm not _stupid_. I know you're not a monster," they said. "You've got your weird hand thing and weird code writing. And…" They grimaced a bit. "…and you kinda look the way I feel whenever there are events. Like you don't really fit in."

Gaster swallowed, then looked down at the Core below. "Well…I suppose I…" He looked up as the railing shook, and his heart flipped as he saw Chara climbing up onto it. "Chara, _stop!_ "

They looked up, then half-smiled as they moved to sit on the lower bar of the railing, resting their arms on the top. "So I'm guessing Mom told you about how I got here." They rested their chin on their arms, dark eyes reflecting the red of the magma below. "Don't worry. I won't jump."

Gaster watched them for a moment longer, then let out a breath as he leaned against the railing, keeping an arm's distance between himself and Chara. He was silent for quite some time, then said, "Yes. I do."

Chara looked up, then frowned a bit. "Does it ever get easier? Do you ever forget you're not a Monster?"

Gaster shook his head.

Chara sighed, once again resting their chin on their arms. "Did you hate the other skeletons?"

"What?" Gaster stood up straight. " _God_ , no. They…my village was destroyed in the war. As far as I am aware, I am the only one left."

"Did Humans kill them?" Chara asked softly.

"Yes."

Chara let out an angry breath. "I hate humans. They ruin everything. I mean, you guys shouldn't be down here! It's only because they don't like things that aren't them!"

Gaster blinked. Were…they serious? They couldn't be. Who could hate their own race that much?

Meanwhile, Chara just frowned harder. "Why didn't you guys fight harder? You could have killed them all!"

"We did fight," Gaster corrected. "I fought…"

"You don't count, you're not a Monster."

"Well, your father fought, as did Gerson and several others."

"But it wasn't _enough!"_ Chara exclaimed. "If they'd fought _harder_ , they would have _won._ "

Gaster sighed. He couldn't say he disagreed with the child. "True, but…it is not in a Monster's nature to fight. They do not enjoy it; honestly, it is hard enough for them to even start a fight."

" _Why_? Humans fight! What's stopping Monsters?"

Gaster blinked. There was no why. It just always was. Right? "I…have never asked myself that. I do not know."

Chara huffed, chin once again on their arms. "Well, it should've been the other way around. You guys should've stayed above ground."

Gaster gave a small, bitter laugh as he leaned against the railing. "I cannot disagree with that."

The two sat in silence, watching the roiling magma and steaming machines down below. Gaster couldn't imagine what Chara was thinking, but he was already far down the road of another hypothesis. Why _did_ humans find it so much easier to fight? Perhaps there was something in their being…maybe even their Soul…

"I should get going. Mom's going to freak out soon."

Gaster looked up as Chara swung around and lightly jumped down from the railing.

"Do you need me to guide you back?"

"Nah, I paid attention." Chara puffed out their cheeks, looking off to the side. "Thanks, I guess. For not snitching on me."

"It was only fair," Gaster said with a shrug. "Tell your parents 'hello' for me."

Chara nodded, starting to go down the stairs. After a few steps, they stopped.

"Dr. Gaster?"

"Yes, Chara?"

"Do you…are you glad you live with the Monsters? Even though you…don't feel right?"

Gaster nodded. "Yes, absolutely," he said. He drummed his fingers on the railing. "The more effort you put in to acclimate to their culture, the easier it becomes."

Chara put on a resolute face and nodded. "I'm gonna fit in," they said. "I'm…I'm determined to be one of them, even if I can't do magic. Thanks, Dr. Gaster."

Gaster blinked as Chara ran down the stairs.

 _Determined_ to be a Monster.

Well, that was a funny thought, wasn't it?


	15. Evaluation

True to their word, Chara did their best to fit in with the monsters. Gaster, of course, could still see the awkwardness, the doubt, the second-guessing—but, then again, it wasn't all that long ago that he had been in Chara's shoes. Maybe Toriel was right.

Except…she wasn't.

Humans and monsters _were_ fundamentally different. There was that… _drive,_ that inclination toward conflict. But why? What gave them that? Was it a mere matter of being more solid than monsters? Was it simply a cultural development? Or was it something deeper, something that was more intrinsic to humanity as a whole?

The question rattled around in his skull for weeks, distracting him from his textbook. Half-baked theories were scattered around the lab, but he was still no closer to finding the answer to the question of what made humans… _humans._

Of course…there _was_ a way to experiment. After all, there _was_ a viable candidate for study in very close proximity. And surely something like this would benefit monsters as a whole.

Yes, this was a good idea. He had no doubt that Asgore and Toriel would agree.

* * *

"Absolutely _not!_ "

Gaster winced at the tandem dismissal. Really, he should have had some doubt going into this. He stood up straight and held up his hands.

"Please, hear me out," he said quickly, looking between the two frowning monarchs. "We have never had an opportunity for a study like this before. If we can study Chara, we may be able to find out what makes humans so _different._ So, when the Bar—"

"Chara is _not_ different," Asgore said firmly.

Gaster couldn't help his irritated huff at that. But before he could argue, Toriel added, "And they are certainly not a…a _lab rat_ for you to poke at. This is absolute _nonsense_ , Gaster."

Gaster set his jaw, hands twitching out a few irritated words before he forced them down to his side. "As well-intentioned as you both are, Chara _is_ a human. And this study will give us the opportunity to _understand_ humans." Both Dreemurrs opened their mouths to argue, but he waved his hands quickly and blazed on, signing wildly. "And if we _ever_ intend on getting out of this hole and getting back to the Surface, then we _must know_ what we are up against, or else we will only be _forced back into this_ _tomb!_ "

His voice had grown steadily louder as he spoke, with the last few words being shouted out. He stopped to catch a breath, and Asgore and Toriel stared at him. They'd never heard their friend get so loud. Gaster flexed his hands and swallowed before drawing back into his usual collected pose before speaking again.

"So…so I believe that it would be in our best intentions if we—"

"I'll do it."

All three turned back to the throne room's door. It was slightly ajar, and a pair of dark, wide eyes stared out at them. Toriel sighed.

"Chara, what have I said about eaves—"

"I want to do it," Chara interrupted again, stepping into the room. They looked at their parents, their chin lifted. "If it can help us fight the humans, then I want to do it."

Asgore sighed. "We aren't going to fight anyone," he assured. "And besides, we…"

"See? This is just what Dr. Gaster said!" Chara exclaimed. They let out a little breath as they looked up at their parents. "Look…I know I'm different. I don't want to be, but I am. And…and if I can help monsters figure out how to get back on the Surface, then I wanna do whatever I can."

"So do I!" The door opened a bit more, and Asriel poked his white head in.

Toriel grimaced, then looked up at Asgore. He gave her an awkward little shrug, then walked up to Chara, kneeling down to meet them eye-to-eye.

"You're sure you want to do this?" he asked seriously.

Chara nodded resolutely.

Asgore sighed, then set his large paws on Chara's small shoulders before meeting their eyes again. "No matter what happens," he said quietly, "you are Toriel and my child. And we will always, always see you as just as much of a monster as Asriel. And we love you very, very much."

Chara wrinkled their nose. "I know, Dad. Jeez, you don't have to get so gushy."

Asgore gave a little laugh, then pulled Chara into a hug. He looked down at them. "If you're sure—really, really sure—then you can take part in the experiment," he said, then looked up. "And Asriel can, too."

Chara gave Asgore a bright grin, then ran back to Asriel's side to chatter about how they were going to defeat the humans. Gaster nearly felt as giddy as the children; imagine _everything_ they were about to learn! His bright spirits were dampened slightly as Toriel walked up to him, eyes steely. She looked at him in silence for a long moment, mouth drawn in a hard line, then let out a breath before narrowing her eyes.

"Remember what I said, Wing Ding," she whispered. Her voice was barely audible, which made it all the more intimidating. "You harm one hair— _one. hair._ —on my child's head…"

"And my life is hell," Gaster finished dryly. When her expression didn't lighten, he sighed. "I _swear_ , Toriel. Chara will be completely unharmed." He looked up at her for a moment, and he couldn't stop the bright grin that spread across his face. "And just think about the books they will write about _this._ "

* * *

He took a few days to create a fully formed hypothesis, as well as develop the tests he wanted to do while he had the children. One physical examination, and then the rest would be exercises to test the way Chara solved problems differently than Asriel.

The physical examination was first, and much to Asriel and Chara's delight, he pulled them out of school for their visit to the university. However, their excitement quickly soured as Gaster gave them impromptu science lesson while they walked.

"Now, both of you are experiencing, first-hand, the scientific method," he said as they walked through New Home. "First, you start out with a question. In this case, why are humans different from monsters? When you have your question, you must form a hypothesis, which is a guess as to the answer of your question. My hypothesis for this experiment is that there is something _mental_ that makes them different. Now we come to the fun part…"

" _Sure_ ," Chara muttered, rolling their eyes.

Gaster ignored them, clapping his hands together as they walked through the University's door. "…which is the _experiment!_ The experiment, naturally, is testing to see if your hypothesis is correct." He turned around to look at the two, sockets bright as he walked backwards. "Now, Asriel, in our experiment, you are what is called the 'control'."

Asriel tilted his head. "The what?"

"The control. You are the, er…the baseline. That is…" He let out a breath and signed a couple words as a few students quickly stepped out of his way before he could run into them. "You see, we already know how monsters work. It is…it is familiar. But it is difficult to think of that while testing. So you will perform the same tests as Chara, and we can see how Chara's choices and actions differ."

Chara frowned. "But Asri—"

"Dr. Gaster, watch out!" Asriel interrupted. Gaster turned around and quickly dodged an obviously late student running to class. He gave a little smile.

"I suppose it would be best if I watch where we are going," he said, then looked at a few of the doors' numbers before walking again. "You were saying, Chara?"

"Asriel's a boss monster," Chara pointed out. "That's different."

Gaster nodded. "Yes, this is true. If you two were older, we would not be able to do this experiment. However, from what your parents have told me, there are very few differences between a child monster and a child boss monster. So, since you are both young, he is able to be used as the control." He stopped to examine another door number, then smiled at the two children. "Here we are. Follow me."

He opened the door and ushered the two in, then looked up. The room was large, and very sterile, with a few medical instruments on nearby tables. Most notably, though, was the large machine in the back of the room, humming quietly. A cat monster was fiddling with the large control panel next to it, and she looked up as she heard the door open.

"Dr. Gaster!" she said brightly as she walked over. "Oh, I am _so glad_ to finally meet you!" She quickly took his hand to shake; Gaster grimaced slightly as he caught the quick glance to the hole in his hand. However, her attention was quickly diverted to the two children. "And _these_ must be the Dreemurr kids! Pleased to meet you two as well. I'm Dr. Felis, head of the biology department here at the University."

"It looks like a hospital," Chara said bluntly as Asriel shook Dr. Felis' hand. She gave them a smile.

"Well, yes. You see, we study monsters' bodies, so it's necessary to have it be a little medical. Though it _is_ a little too white in here for my taste."

Chara gave a little nod, and Asriel pointed to the machine in the back.

"What's _that_?"

" _That_ is why we are here," Gaster said with a wide smile. Felis nodded.

"What we have here is the first of its kind," she said, guiding them over to the machine. "We call it a Soul Level Scanner, or the SLS. What this machine does is scan deep inside you so we can look at your Soul."

Chara frowned. "Why would you want to do that?"

Felis gave them a bright grin. "Well, if we can peek into someone's Soul, then we can get a read of how strong they are, how healthy they are, and what condition their Soul is in." She grabbed a black and white sheet off of a nearby table, holding it up. "Here, this is the reading from one of our students." She pointed at the white heart in the middle of the sheet. "This is what his Soul looks like. And here…" She pointed to the numbers on the side of the sheet. "…are his 'stats'. You see, his health is at 40, and his strength and defense are both at 12."

Chara pointed at the 1 at the bottom of the sheet. "What's that fourth number?"

"Why, that's something we call 'Level of Violence'. We…still haven't quite figured out how to measure that, but that refers to the state of the Soul. Souls can change if you get too violent, and we're figuring out how to measure that change."

Gaster nodded, hands moving impatiently. "Yes, yes. Now, I have brought you both out here so we can scan your Souls, just in case there is any difference between them."

Both Chara and Asriel looked apprehensive, and Asriel took Chara's handbefore he looked up at Felis.

"Will it…will it hurt?" he asked in a very small voice. Felis shook her head with a smile.

"It won't hurt a bit."

"That's what grown-ups say when something's gonna hurt," Chara muttered with a frown.

Gaster tapped his fingers together anxiously as both children looked increasingly distrustful. No, no, _no._ If they weren't scanned, he'd miss the physical aspect of his study, which was immensely important. But, if he made them do something that scared them, the Dreemurrs would shut down the study immediately. If he wanted to go forward, he had to…he had to _reassure_ them. He had to convince them that this would be fine.

He took a breath and, as easily as he could, suggested, "Well, I could go first." As both kids looked up at him, he smiled. "If the machine hurts me, then obviously you two would not go near it. But if it does not, then it is safe for you to go. That sounds fair, does it not?"

Chara frowned. "But you don't have skin."

"That is an excellent observation, Chara. But I _do_ have a Soul. And, if this machine works the way Felis says, then only my Soul will be scanned. Is that correct?" Gaster asked, looking up at Felis. She nodded.

"Yes. And all of our volunteers—most of which had skin, by the way—have said that there was no pain at all," she assured.

"You see? They conducted an experiment, just like we are. That way we know it is safe." Gaster watched the two children anxiously, his fingers twitching out his thoughts.

 _Please say yes. Please,_ please _say yes._

Chara looked to Asriel. Asriel looked to Chara. He gave a little smile before nodding. Chara squeezed their brother's hand, then looked up at Gaster and Felis.

"Okay. We'll do it."

* * *

The SLS was…cramped. Even though Gaster was very thin, he still felt a little claustrophobic in the metal tube. However—even with Felis taking quite a few minutes talking to him about what an inspiration he was and would he _please_ consider coming back for another talk at the University?—the scan was over quickly, without the least bit of pain. So, with a clear conscience, he told the children that the scan didn't hurt.

Asriel was first. He came out not long after talking about how it tickled a little bit. Chara was apprehensive before their turn, but with some encouragement from Asriel, they went into the scanner next. And just like that, they were done.

"Looks like everything went just fine," Dr. Felis said, smiling as Chara practically ran back to Asriel's side. She looked up at Gaster. "Everything should have been picked up, but I'll call if we need to do a re-scan. If I don't call back, then you can pick up the prints at the end of the week."

Gaster gave her a nod. "Excellent, thank you. And…" He glanced up at the clock. "…it would appear that we have plenty of time to get you two back to school to finish the day."

Asriel and Chara looked at each other.

"Gee, Dr. Gaster, I dunno…" Asriel started.

"We're _awfully_ wiped from that scan," Chara finished.

Gaster raised a browbone at the two of them. "Do you two _really_ think that the Royal Scientist would allow you to miss out on your education?" Before they could answer, he answered, "No. We are going back to school. Besides, your mother would never let me hear the end of it." He gestured to Felis. "Now, say goodbye to Dr. Felis."

Both children grumbled out a goodbye, and Felis gave them a bright smile.

"Goodbye! Maybe I'll see you two in a few years," she said with a wink, then gave Gaster a smile. "And good luck on your experiment, Dr. Gaster."

Gaster gave her a nod, then ushered the two Dreemurr children out. _Now._ Time for the _fun_ part.

* * *

"I thought you said experimenting was the _fun_ part!" Chara complained, scrunching their nose at the textbook in front of them.

"It is," Gaster assured, writing out his preliminary notes. "This is where we find out if we are right or wrong."

"But this is just _school!_ "

"It is not. We are in the Lab."

"They mean that it _feels_ like school," Asriel said. "And, um…it kinda does, Dr. Gaster. I-I mean, I _like_ school but…" He went quiet as Gaster held up his hand.

"I promise, this is not school," he said. "All I am asking is for you two to find one passage in this book…"

"That's school!"

" _Hush_ , Chara. Please allow me to finish. I want to know who can find it faster."

Chara let out a puff of annoyance. Asriel, meanwhile, sat up. Gaster took notes on each.

"Now," he said, "here is the passage I want you to find: 'And so, seven-hundred years before the Barrier, King Cabral came to the throne, and Monsterkind flourished in his kingdom.'" He pulled out a stopwatch, clicking it. "Start now."

Both books opened, and Gaster watched the children intently. Humans liked the satisfaction of being better, so he assumed Chara would try to find the passage first for their own satisfaction. Though, admittedly, Asriel wasn't the best to test against; the boy had a curious nature, and he'd inherited his mother's desire to learn things just for knowledge's sake. But surely that drive would outdo even the most curious monster in something like this, right?

No. He was wrong. While Asriel's attention wandered—he would take a few moments to read passages that interested him as he searched—Chara was completely disinterested. They would flip to a few pages and idly scan them, but for the most part they merely sent annoyed looks at Gaster. Clearly, that human drive was _not_ in play at the moment. Gaster made a note of that.

"Found it!" Asriel finally announced, pointing to the passage with a clawed finger. Gaster stopped the watch and walked over to look.

"Yes, that is the right one," he said with a nod, patting the boy's shoulder. "You won this round, Asriel."

Chara looked up at the word "won," frowning. "He didn't _win._ You can't win if it's not a contest; you just told us to look stuff up."

Gaster blinked, then gave a small smile. _Ah._ An incentive might be what he needed to get that drive out. He made a quick little note before walking back to the other side of the desk. "I…do suppose you are right, Chara. Let us…er, I believe the term I have heard is 'up the ante.'" He went to the Lab's refrigerator and pulled out a little box. "What I have here is one piece of cinnamon-butterscotch pie. Whoever finds the next passage first wins it."

Both children's jaws dropped; after all, Toriel _only_ made cinnamon-butterscotch pie for special occasions. They both sat up, hands on their books. Gaster looked between the two with a smile, then picked up the stopwatch again.

"The passage you are looking for this time is, 'And in the year 1528, Queen Cornetta established a Royal Guard.'" He clicked the watch. "Start now."

This time, both children were a flurry of turning pages. Asriel's reading was more focused, but Chara…their face was sharp, eyes darting over pages for less than a second before turning to the next. Soon enough, they slammed their hand down onto the book.

"Found it!"

Asriel looked up, and Gaster was quickly at their side to make sure it was the right passage. He nodded, jotting down notes as quick as he could.

"It would appear that this round goes to Chara." He slid the box over to them, along with a little plastic fork. "Congratulations."

Chara grinned, then took a big, victorious bite of the pie. Asriel gave a puff and crossed his arms. Gaster tilted his head.

"Are you upset that you did not win?" he asked. Asriel shook his head.

"No," he said, pouting slightly. "It's just…Chara _always_ gets like this in games. They always have to win."

Chara's victorious look faded as Asriel mentioned this, and they swallowed their bite of pie before looking up at Asriel sheepishly. He nudged the pie over. "Here, Azzy. We can share it."

Asriel glanced up at them, then gave a little nod before taking a bite. Gaster took down a few more quick notes, then sat down across from them.

"Is this true, Chara?"

Chara squirmed uncomfortably. "I'm, uh…well, Mom says I'm competitive."

Asriel snorted, nearly choking on his bite of pie. "It's _way_ more than that. If you don't win, you _always_ demand we try again until you do."

Chara's cheeks went red. "Shut up, Asriel!"

"No, no! This is very interesting," Gaster said, writing down everything. "This sounds like what we are looking for. That…that drive to keep going, keep winning. Tell me, Chara, does this same thing happen with other activities?"

Chara scrunched their nose before shrugging. "I dunno. I never thought about it."

Gaster looked up at them, sockets wide as new questions and theories filled his skull. He smiled. "Well. That is what this study is for."

* * *

With this new knowledge, Gaster was able to tailor the tests to make sure Chara used their drive to win as much as possible. For the most part, it was as easy as saying "Whoever does X first wins." More often than not, Chara won those tests. When they didn't, though, they would insist on a do-over. On the rare occasions where they _could not_ do what was asked, they quit the test in a huff.

However, this drive wasn't only used in interpersonal competitions. During the rare times Asriel wasn't there, Gaster gave them a few timed tests and puzzles; each time, Chara would ask for another go so they could improve their time. There was this strange... _determination_ to be better, to progress for the sake of progression.

This _Determination_ —for lack of a better term, that's what Gaster was calling it—did bring some reason into Chara's actions. Of course they would try their hardest to be a monster; they wanted to blend in, and were unaware that, ironically, this obsession with being _more_ monsterlike only made them more _human._

Now, of course, came the difficult question. How would this affect humans in _battle_? Did Determination make them want to kill for the sake of killing? Was it to prove they were stronger or smarter than their opponents? Or was it just progress for them?

Of course, this sort of test would require a different sort of environment. It was also imperative that Toriel and Asgore _did not know_ what this test entailed. To them, Chara was a symbol of peace.

To Gaster, they were a key in how to win the war.

Luckily enough, there was a lower level to the lab. There were a few, actually; most were designed for storage, but the bottom one…the bottom one he had designed for any sort of… _confidential_ work. Things that the Underground as a whole didn't need to know, perhaps even things that Asgore and Toriel didn't need to know.

Of course, he hadn't needed to use it just yet, so it was rather empty right now. Making it the perfect place for battle practice.

Today, he'd asked that Chara come alone, and he was surprised at how readily the child agreed. He'd noted that the tests had made Chara more confident; perhaps utilizing so much Determination was bringing Chara out of their shell. They had never been a _demure_ child, of course, but lately it seemed that they were leading Asriel now, rather than the other way around. They arrived, rosy-cheeked and smiling, and Gaster wasted no time in ushering them into the elevator.

"So what's the test today, Dr. Gaster?" they asked during the long ride down. "Why couldn't I bring Asriel?"

Gaster glanced down at them. "Well…this is our last test. And I thought it best if I see the way _you_ react in the situation I am about to present."

"I'd react either way," Chara said with a frown. Gaster shook his head.

"Asriel tempers you. He…softens your reactions. For this experiment, I want to see you behave as just Chara, not Chara Dreemurr." He tapped his fingers together. "And you _must not_ tell your parents or Asriel about what this test entails."

Chara's dark eyes went wide. "Are we doing something _illegal_?"

"No, no, of course not. But…I get the feeling your parents would not approve."

The elevator came to a stop, and Gaster held the door open as Chara stepped out. They frowned at the dummy in the middle of the room, then looked up at Gaster.

"So…what are we doing?"

Gaster looked down at them, then clasped his hands together. "Today, we are seeing what you do in battle."

Chara's expression darkened. "I can't do that."

"Well, this isn't…"

"No, I mean I really can't. I…" They looked down, hands curled into fists. "I can't do magic. I keep trying—I try really, really hard!—but I just…I can't."

Gaster tapped his fingers together. He knew that, of course. But perhaps this attitude would make them a reluctant fighter? That could be interesting.

"Yes, well, I anticipated something like this," he said, turning to a nearby table. He picked up a little leather case, then held it out to Chara. "I expect this will help you much more than magic."

Chara looked up at him dubiously, but took the case and opened it up. Their eyes went wide, and they pulled out the knife inside. They studied it intently.

"Is this…are you giving this to me?" they finally asked, looking up at Gaster with wide eyes.

" _Only_ for the sake of this experiment," he replied firmly. "Once it is over, you leave it here."

"But…but what if humans attack? What if we need to defend ourselves? What if—" They stopped as Gaster held up a hand.

"We have other ways of managing that. For now, let us focus on the present. We have a test to do." He led the way over to the dummy, gesturing to it. "Here is your opponent."

Chara frowned. "That's not much of an opponent."

"I know, but I am not willing to fight you and potentially die from a lucky blow," Gaster said breezily. "So you will have to use your imagination."

Chara fiddled with the knife uneasily. "But…I mean, I don't really wanna just _stab_ something because I imagined it's a…a bear or something."

Gaster tilted his head. He wasn't expecting that; he thought humans enjoyed fighting itself. Perhaps he was wrong. "Well, what _do_ you want to fight?"

"Humans." This came with no hesitation.

"Then this dummy is a human." Gaster took several long steps back as Chara's expression changed. "It is the human you hate the most. I know you have at least one human you hate; you would not have come down here otherwise. So that person is now standing in front of you."

Chara took a deep breath, though they didn't make a move to fight. Gaster let out a breath. This could be a dud. But all this work for nothing? No. Chara wasn't that well-acclimated. He could force them to fight. He just had to push the right buttons.

"Did the human hurt you?" he asked loudly from the sidelines. Chara didn't answer. "Now is the time to take your revenge, then! Hurt them! Make them pay for what they did!"

Chara grimaced, adjusting their knife in their hand. Gaster was getting impatient. He let out a huff before shouting, " _Hurt them! Fight them!_ "

"I-I…"

"Asgore and Toriel are wrong!" Gaster shouted from the side. "You know they are! You know you want to hurt those that hurt you! So _do it,_ Chara!"

" _Shut up!_ " Chara shouted back at him.

"Are you afraid? Are you _scared_ of them? You have the power now! Make them pay! Make them hurt! _Do it, Chara!_ "

Chara gritted their teeth, and with a scream of rage, they charged forward. The knife plunged into the dummy. Then it plunged in again.

In all, that wasn't very noteworthy. Even a monster would snap after that much provocation.

What was startling was that Chara _kept going._

They stabbed the dummy over and over. Stuffing leaked out onto the floor, but Chara kept stabbing, kept ripping at the fabric. The knife plunged into the head, the body; it clanged against the metal bar holding it.

Gaster was dumbstruck at the sight. This, of course, was the reaction he was looking for. That drive to keep going and fight harder.

But it was hard to watch. Especially since, even after all these years, he remembered doing the same thing to a human's corpse on the surface.

Finally, enough was enough. He had to snap Chara out of it.

"Chara. _Chara._ The test is over, Chara, you can stop!"

They didn't stop. Tears leaked from their eyes and ran down over their red cheeks as they kept stabbing.

"Chara, this is overkill. It is over, there is no human here!"

Chara didn't stop.

Gaster hesitated, then walked over quickly. "Chara, it is _time to stop._ It is over." He huffed as they didn't listen. He reached over to pull the dummy away.

 _"Don't get in my way!_ "

Before he could move any closer, the knife plunged into his middle.

Both he and Chara stared at the knife's hilt, buried deep in his sweater. Chara's expression turned to one of horror.

"O-oh…oh _no…_ "

Gaster blinked, pulled out of his shock as the knife clattered to the ground. Chara drew away, eyes wide.

"No, no…n-no, Dr…Dr. Gaster, I-I…"

Gaster blinked again, then looked up at Chara as they sank down to the ground and dragged their hands down their face.

"N-no. I-I am all right. Just…er…really, I am fine. Er…" He lifted the sweater, showing the empty space in front of his spine. "You see? Nothing there. It is fine. I am fine."

He looked down at Chara, then let out a breath and sat down across from them. His browbone furrowed as they held their head, drawing into themself, and he sighed. "I…I think I pushed too hard. I am sorry. I—"

"It was so easy," Chara whispered, so faintly that Gaster could hardly hear it. So quietly he probably heard it wrong.

"Er…what?"

Chara shook their head, still keeping it against their knees. "It was _so easy_ ," they whispered again. "I didn't even think. I just…did it." They looked up at him, dark eyes wide. "I could do that to anyone."

Gaster stayed silent for a moment. They weren't wrong, of course. If they could get into that sort of frenzy, of course they could kill anyone. He let out a breath.

"Chara." They looked up at him. "You were put under duress. I doubt that you could kill someone on a whim."

"But I have Determination!" they argued. "Asriel would never do what I just did! Asriel wouldn't kill someone just because! I almost did! Only a human would do that!"

"Only a human with an intention to harm," Gaster said evenly. "You wanted to hurt the dummy. I got caught in the cross-fire. In this sense, yes, Determination is dangerous. But…"

"No. I wanted to hurt you."

Gaster blinked. "What?"

Chara swallowed. "When…while I was fighting the dummy, I wanted to completely destroy it. I-I couldn't stop until it was completely gone. And since you…since you interrupted, I wanted to hurt you, too. Because you were stopping me."

Gaster stared at them silently, brain working. So. Determination was greater than seeking progress or wanting to win. Determination was about seeing something through to the end. Chara wanted to destroy the dummy; the human armies wanted to eradicate the monsters. Each were only deterred by something insurmountable—a mountain, a conscience—getting in the way. But do away with those barriers, and…

Well. Better not to think about that.

But…imagine if a monster's magical power was combined with that drive to see things through. That drive to progress and fight and _win_. Why, they could…

"Dr. Gaster?"

Gaster was broken out of his reverie by the quiet voice. He looked down at Chara, who watched him with big, dark eyes.

"Am I as bad as the humans up on the Surface? For…for what I did?"

Gaster tapped his fingers together. They were certainly just as dangerous. One bad turn, one bad day, and…

"No. No, you are not bad."

They stared at him a moment longer, their brow furrowed. Finally, they nodded and let out a breath.

"Okay. You don't like me enough to lie." They swallowed. "But…but please don't tell Asriel what happened."

"Of course not. This stays between us." Gaster watched Chara for a moment longer, then got to his feet. "Well. I think that is the end of our experiments. I…I have learned quite a lot." He hesitated, then held out a hand to help Chara up. "Come. You will be just fine after a hug from your parents and some rest."

Chara got up, letting go of Gaster's hand once they were on their feet, then trudged their way to the elevator. They looked like they had fought a real battle. In a way, Gaster supposed they had.

He stood beside them as they went up, skull buzzing excitedly. He had _so_ much information from this. He couldn't wait to write it all down. Now all that was left was to wait for the prints, and he could start formulating his theory of Determination.

* * *

The prints came later that afternoon. The intern handing them over asked about the hole in his sweater; he casually blamed it on snagging on a piece of equipment and left before any further discussions could take place. It was all he could do to stop himself from running to the Lab.

Once in the lab, he pulled out the three prints and laid them out on one of the tables. The first, which had the highest stats, was obviously his. He frowned at a gray spot on the white Soul—someone had clearly gotten careless and smudged it. Well, no matter. He pushed it aside and turned his attention to the other two.

The stats were practically identical. But, while one Soul was pure white, the other was dark through and through.

Well.

It seemed there _was_ a fundamental difference between humans and monsters. Determination came from the _Soul._

A bright grin spread across his face, ideas bouncing around his skull so fast it threatened to explode. There was no time to waste with writing things out. He had to get to Asgore and tell him his discovery.

Perhaps freedom was closer than they thought.


	16. Emergency

Less than ten minutes after a frantic, nearly incomprehensible phone call to Asgore, Gaster barreled into the Dreemurrs' home, scan prints in hand. As was requested, both Toriel and Asgore were waiting for him in the Throne Room, looking more than a little confused as he entered. He didn't even greet them, instead turning to lock the door behind him.

"Now, Gaster, that seems a bit extreme," Asgore said with a frown. Gaster shook his head and waved his free hand.

"I know your usual policy, Asgore, but I _also_ know you have two eavesdroppers in the house." He turned to look at them, sockets bright. "And, for the moment, I would like to keep this information to just ourselves."

Toriel's brow creased. "Did you…find something with Chara?" she asked hesitantly.

"Yes! And it was something that I could not even imagine!" He walked over to them with a wide smile, holding up the prints. "Look at this!"

The two royals glanced at each other apprehensively, but stepped forward. Despite their obvious hesitance, Gaster's smile didn't dim in the least.

"As you two know, Chara and Asriel were both scanned with the SLS at the university, so that I could see the state of their Souls. Now, truthfully, I only did this for, ah, for the sake of thoroughness. They are both very young, which means I did not anticipate anything outside of the ordinary with their Soul levels. But I was _wrong!_ So outrageously wrong!" He held up one of the prints for them to see. "This is Asriel's Soul. It shows up white in the scan, just like a typical Monster Soul. But when we look at Chara's scan…" He held up the other print, just barely keeping his hand steady as he practically buzzed with excitement. "Chara's Soul is _dark!_ "

Asgore looked over the prints, stroking his beard thoughtfully as he mulled over the find. Toriel frowned curiously at the prints, then pulled out a pair of reading glasses to get a better look. Gaster could see how she was struggling between wanting to know more and continuing to say that Chara and Asriel were exactly alike. After a moment, she let out a breath and looked up at Gaster.

"Well, this is…certainly interesting, I will admit." She took off her glasses. "Do you know why this is?"

"I was hoping you would ask that." He set down the prints let his hands sign wildly as he spoke. "I have a theory. I believe…I believe that Determination is a type of Soul Magic!"

He paused, waiting eagerly for their reactions. But, rather than gasps of astonishment, he merely got a pair of blank looks.

"Um…'determination'?" Asgore asked after a moment, tilting his head curiously. Gaster blinked, then shook his head.

"Of course, of course. My apologies. That, er…that is the term I have been using in the tests." He tried to still his hands in order to speak as clearly as possible. "Determination is that…that human desire to see things to completion, whether they realize it or not. While I am sure it…it, er, influences many aspects in a human's life, it appears to affect Chara most in…er, in competitive settings. You see, in the tests, Chara _always_ had to push themself to do better. It did not matter if they wanted to win against Asriel or merely improve their own performance. They _had_ to do better, they _had_ to complete the task, or they were left unsatisfied."

Toriel crossed her arms. "And you think that this…Determination has to do with their Soul?"

"Yes!" Before he could stop himself, Gaster began pacing around the throne room, hands everywhere as his thoughts poured out. "If Determination is indeed the reason for their colored Soul, then it would make sense why they cannot use magic. This _is_ their form of magic! This is the core of their being! Just _imagine_ the possibilities now that we know _what_ makes humans tick! Obviously we will have to do more tests, as this was just a prelim—"

" _More_ tests?" Asgore grabbed Gaster's arm, turning him to meet his gaze. "Surely this has been enough. I mean, you got your answer…"

Gaster stared at him as he pulled his arm away. "Got my…are you _joking?_ A whole _world_ of information has just opened for us! Think of the _progress_ we could have! If this really is Soul Magic, then Determination can be used in the same way _we_ use magic! And if there was a way to…to _channel_ it out, like we do when we use healing magic, then it may be able to be used by others! We could…we could find a way to give it to Monsters! Imagine, with Determination _and_ magic, we may even be able to trick the Barrier. If we can find a way to-to give our strongest monsters Chara's drive, we could _take back_ the Surface from the humans and—"

 _"Enough._ "

Gaster stopped and turned to look at Toriel. Her eyes were ice-cold, her mouth hard; he even thought he could see her shoulders trembling from anger.

"Chara is _not_ a science project," she said through her teeth. "And they are _not_ something for you to _weaponize._ "

Gaster frowned. "I am not weaponizing _Chara._ But the fact is that they are the _key_ to—"

"They are not, and I forbid you from continuing these experiments!" Toriel snapped.

Gaster stared at her, hands stilled in shock. After a moment or two of stunned silence, he turned to Asgore, who looked equally surprised. "Asgore, surely you see why these studies are _essential_."

Asgore opened his mouth, but Toriel interrupted. "Asgore has seen what has happened to Chara since your _experiment_ ," she spat. "They have barely spoken. They do not sleep. They have been _mean_." She shook her head sharply, hands closing into fists. "They will not say what happened, but I _know_ it was due to you. And…and with all this talk of…of Determination and starting _another_ war with the humans, I just…you cannot…" She took a breath and steadied herself, then fixed her steely glare on Gaster. "With the way it seems your research is heading, it may be best if you are relieved of your duties as Royal Scientist."

Gaster stared at her with wide sockets, too stunned to even move. _Relieved_ of his duties? He was being fired because of an _experiment_? A strangled noise left his throat as his hands jerked incomprehensively. His life had been devoted to his work as a scientist. _What could he do if that was taken away?_

He finally turned his gaze to Asgore, silently pleading for him not to do this.

Asgore looked just as taken aback. He looked between his wife and his friend, then held up his hands. "Let's…let's not have any knee-jerk reactions. What Toriel means is…"

"You _know_ what I mean, Asgore Dreemurr," Toriel hissed. "You have seen it. You have seen the way Chara slinks away, the way they don't look at us. All of our work was undone because _he_ —" She pointed hard at Gaster. "—wanted to weaponize a _child!_ "

With some effort, Gaster found his voice. "I…I a-am a _scientist_ ," he said as firmly as he could. "My life is devoted to finding answers, _your highness._ I found the answer to why Chara was different."

"Only because you wanted to rub it in their face," Toriel snapped back.

"It was _necessary!_ " he argued, hands moving sharply."I _gave_ them answers. Now, when they feel different, they have a concrete _reason_ to consider! Really, Toriel, if you truly loved Chara, you wou—"

A fireball just barely missed Gaster's cheekbone.

"Oh my _god_ , Toriel!" Asgore grabbed Toriel's arm, jerking it down. "What _was_ that?"

Toriel didn't respond. She stared hard at Gaster, eyes filling with tears.

"I have done… _everything_ because I love them," she said, voice trembling. "I do not understand why you are so set on undoing everything Asgore and I have done. I know you hate humans, but you…you cannot be _that_ cruel." A few tears spilled out, matting the fur on her cheeks. Asgore quickly set his hands on her shoulders as she whispered, "You cannot hate an innocent child enough to ruin their happiness out of spite."

"But I…" He trailed off, hands falling to his sides. Did he want to ruin Chara's life? Was he just seeking answers about humanity?

Or was there something, lodged deep, deep below the layers of mistrust and prejudice, that wanted to help another outsider understand and come to peace with their inherent differences from the people they loved?

It was quite possibly a mix of all three. He'd never really thought about it before now.

Toriel ruffled the fur on her cheeks. "You can tu-turn in your badge and—"

" _No._ "

Toriel turned to look at Asgore in surprise. He squeezed her shoulders, then let out a breath.

"Tori, we can't make knee-jerk decisions, not with the way things are down here," he said quietly. He looked up at Gaster. "Even…even if what Toriel says is true—though I hope to _god_ it isn't—you're the only one who knows the Core well enough to oversee its operation. But…but this talk of fighting is absolutely out of the question. We don't want another war." He sucked in a breath as he stepped between the two. "So, let's compromise."

"I do not…" Toriel began, but Asgore held up a clawed finger.

"Gaster _will_ remain the Royal Scientist." He turned to look at Gaster. "But I'm ordering that all research on Determination is terminated."

Gaster's hands twitched out a few frustrated words, but he nodded silently.

Asgore nodded in return, then took a breath and added, "And…you are not permitted to see Chara if Toriel and I aren't there."

Gaster blinked, unsure if he heard correctly. When he realized he had, his hands were everywhere. "I am not a danger!" he exclaimed. "Do you think I am so…so _deranged_ I would go against my word?"

Asgore grimaced. He seemed to weigh things for a moment, then shook his head. "No, but…we can't take any risks. For whatever reason, Chara is…not themself, and…and this may help."

Gaster huffed. _Unbelievable_ , he signed, but he gave a silent nod. "Well, it would appear I have said all I can. I humbly ask to take my leave," he said dully, looking at the two of them.

Toriel ruffled the fur on her cheeks again. "You may go," she said quietly. Asgore nodded in agreement.

He took his prints with a sigh, then turned and made his way out. As he unlocked the door and opened it, he noticed a small glass cup left on the ground. He furrowed his browbone, then picked it up.

Well. Looked like someone had been eavesdropping.

He frowned slightly, then set the cup on one of the side tables. No doubt Chara was the culprit, and they were, apparently, nothing he should concern himself with. So, let Asgore and Toriel deal with explaining Determination to Chara.

They _obviously_ knew best in this situation.

* * *

Loneliness, he was finding again and again, suited Gaster.

He supposed that this shouldn't be much of a surprise anymore, considering the way his life had gone thus far. But, in the six months he spent all but barred from dinners, engagements, and other socializing nonsense, he was able to get a tremendous amount of work done. He finished his textbook, and was now writing up a curriculum for a Magic and Physics course at the university—to be taught by someone else, of course. With so much progress, perhaps it was best that his relationship with the Dreemurrs became entirely professional.

Well. That's what he kept telling himself, at any rate.

But the near-dismissal _had_ left a bitter taste in his mouth, so, for the most part, he didn't miss meeting for tea or visiting New Home as much as he'd imagined he would. And, with some time away, Gaster _was_ realizing that Toriel and Asgore weren't the same as they were ten years ago. It was entirely possible that it was time for them to part ways as friends, and only carry on as colleagues.

Even so...he did wish, every now and again, that he had someone besides the Core's puzzle operators to talk to.

It was right on the end of one of these sentimental moods that the lab's phone rang. For the most part, the party calling would have to try two or three more times before he deemed it important enough to answer. Today, though, a lingering loneliness prompted him to pick it up on the first ring.

"Hel—"

"Come at once." Toriel's voice, high and strained, came through the receiver.

"I—what?"

"Asgore is ill. Please, _please_ , Gaster, come quickly." The line went dead.

Gaster stood very still, phone still in his hand. Asgore? _Ill?_ It had to be quite bad for Toriel to be so panicked. Did she think he could help? Or…did she want him to say his goodbyes?

 _No._ It _had_ to be to help. Asgore _would not_ die.

But his specialty wasn't in biology! He only knew the basics…

Oh, for god's sake, he was the _Royal Scientist._ If he could build the Core from the ground up, he could figure out how to heal Asgore.

Fast as anything, he sprinted up to the second floor of the lab, gathering a book on biology and a few pieces of equipment that might be helpful. He dumped it all into an old rucksack, then tore out of the Lab. There was no time to waste.

* * *

The door was unlocked, of course, so Gaster went straight into the home. Inside, things were deathly still. He felt something twist inside him, his mind screaming that he was too late. _No._ He was not. He took a breath and went straight to Asgore and Toriel's bedroom—that had to be where they were. Just as he reached for the doorknob, the door swung open.

"Oh!" Toriel jumped slightly as she saw him, then let out a sigh of relief. "Good, you are here."

"How is he?" Gaster asked quickly. "I brought what I could. If we call some stronger monsters, we may be able to…"

Toriel held up her hands, and Gaster fell silent. "That is our very last option," she said. "For now, I will do what I can with magic."

A pained expression crossed Gaster's face. "I cannot help with that. My healing is…" Toriel held up her hands again.

" _Yes_ , you can help," she said firmly, then pulled from her pocket a paper with a few scrawled notes on them. "Here. Three recipes for tinctures; the ingredients are in the kitchen. It is practically chemistry." A low groan came from inside the room, and she shoved the paper at him. " _Hurry,_ Gaster!"

He gave a quick nod, then turned and practically ran to the kitchen. He looked over the three recipes; it really _was_ like chemistry. He gathered up his ingredients, then turned his focus to the task, just like he did in the Lab.

He was carefully measuring out his chopped Valerian root when he felt a small tug on his sweater. He glanced down just long enough to see which child it was before returning to his work.

"I am quite busy, Asriel."

"I-is Dad gonna die?" The whimpered question earned another glance down from Gaster. Asriel's eyes were wide and wet as he stared up at him.

" _No._ Your father will be fine."

"But…but he's never been this sick!" Asriel wailed, voice catching. "We shouldn't've made the pie!"

"God, Asriel, don't be such a crybaby."

Gaster looked up sharply at the voice. Chara slumped in the doorway, knitting needles and what looked like a half-finished sweater in hand. They gave a little shrug.

"He's not gonna die," they said flatly. "No one dies from _flowers_."

"Flowers?" Gaster looked down to Asriel, who sniffled and ruffled his tear-matted fur.

"W-we tried to make Mo-Mom's butterscotch pie. Th-that's Dad's favorite. But…but we thought it said 'buttercups' instead of 'cups of b-butter'." He let out a whimper. "We didn't want to hurt him!"

"I am certain you did not," Gaster said gently, setting a hand on Asriel's head before ushering him out. He turned back to chop and grind some nettles before glancing up at Chara, who scowled before exiting.

Well. It seemed that Toriel hadn't been exaggerating about Chara's change in demeanor. But there was no time to dwell on that. He needed to get these potions made.

* * *

It took hours, and several rounds of the tinctures—Lobelia to purge the poison, willow bark and valerian to ease Asgore's pain, and several cups of dandelion and nettle tea to keep Toriel's magic up while she continued to heal him—but finally, _finally_ , Asgore was in stable condition. And, after one last round of anesthetics to help Asgore sleep, Toriel emerged from the room, looking exhausted and older than usual.

In the kitchen, Gaster leaned wearily against the sink. He perked up, though, as she entered. "He is all right?"

"Yes. Still not well, but…well. I do not have to plan a funeral just yet." Toriel glanced up at him, catching his still-concerned look. "Yes, he will be fine in time."

Gaster shut his sockets as he let out a sigh of relief. "Thank god." He opened his sockets to look at her, browbone drawn. "Would you like me to make you some tea?"

Toriel shook her head as she opened up a cupboard. "I think this situation calls for something a little stronger." She reached inside the cupboard, fumbling about a bit before she pulled out a bottle of wine. She held it up for him to see. "Would you like a glass?"

Gaster blinked, but nodded. "I did not know you even had that."

"Asgore and I _were_ raised in royal courts, I'd like to remind you. Some of the tastes stay with you." She deftly used a claw to open the bottle. "Though we only bring out the wine on important dates. I think the last time was our…our hundred-and-fiftieth anniversary."

She pressed her lips together as she poured two glasses, then handed one off to Gaster before heading into the living room. She wasted no time in practically collapsing into her chair. Gaster followed and did the same onto the sofa. For several moments, the two sat in stunned silence, exhausted and overwhelmed from all that had just happened. Finally, after a long drink, Toriel spoke.

"Thank you, Gaster. For your help, and for…just being here."

He looked up. "Of course. You are my friends."

Her brow creased. "Even after…our discussion six months ago?"

Gaster tapped his glass awkwardly. "Well…I did come more for Asgore's sake," he admitted. Toriel sighed.

"I do not blame you," she said quietly. After a moment, she added, "I'm sorry. You were right."

"Pardon?"

"About Chara. I…" she sighed. "They are not like a Monster, and I should have listened and talked to them about that. I think I have hurt them by trying to convince them they are something they are not." She took a long drink. "That…that may be part of the reason they are behaving this way."

Gaster swallowed. "Toriel…about the test, the last one. At the end of it, Chara…" He hesitated. Was it worth mentioning how they had lashed out? Should Toriel be notified about the risk Chara posed? Perhaps, with this buttercups incident…

"Yes?" Toriel leaned forward curiously. Gaster lost his nerve.

"Er…well, I-I think the best course of action is for you to…to find a way for them to use their Determination. In a…constructive?" He looked to Toriel, who nodded. "In a constructive way."

Toriel smiled a bit. "You know, Asgore has already thought of that. He has been teaching them to knit, and they seem to quite like it." She laughed lightly. "They…they even made him a sweater." Her smile faltered, and she covered her eyes. "Oh, god, I was so close to losing him," she whispered. "I-I do not know what I would have done without him."

Gaster watched her sympathetically, then leaned forward to pat her arm. "It is a very lucky thing you had those recipes."

She shook her head. "They were Asgore's. His knowledge of plants is…astounding. And of course he's always trying new things for his teas. He made these notes just before he was dangerously ill." She sniffled a bit. "He always tells me how clever I am, but I never think to tell him the same." All at once, she stood up. "I-I should go be with him. Ah, you are welcome to stay, but I will be…"

Gaster waved a hand, setting his glass down on the coffee table. "No, I think I will go back to my own home. We all need a rest after tonight." He got to his feet, starting to stretch. He stopped as Toriel took one of his hand, looking at her curiously.

"Thank you, my friend," she murmured. "For being here, despite everything."

He smiled gently at her, then gave her paws two quick pats. "Of course. Call me first thing in the morning to let me know how he is doing." He carefully drew his hands away, then quietly left the house.

While he wasn't fond of the way things had gone tonight, Gaster had to admit that, for the first time in a very long time, it felt like things were finally mending themselves. Perhaps the friendship between the three of them was about to rekindle.

He could hope, at least.


	17. Failure

Gaster knew there was no way he'd be able to rest after the past few hours. The stress of needing to save Asgore's life and the rush of succeeding meant his mind was buzzing like mad. He'd be wide-awake for at least several more hours—possibly days, if previous experiences were anything to go by. Going to his home would be pointless; yes, the walk all the way to Snowdin might burn off some of the energy, but not all of it.

So, naturally, he went to the Core. True, the main controls didn't _need_ to be recalibrated for another month or so—and, honestly, he could get one of the workers to do it by this point—but doing it himself right now meant he wouldn't be sitting in Snowdin debating on running the entire length of the Underground. So, thankful he'd kept his ID card in his pocket, he entered the Core and got to work.

He really ought to have been surprised when he heard footsteps come up the stairway behind him. But, honestly, he knew better at this point.

"Whose card did you take?" he asked, not looking up as he examined the temperature gauge for the Core's upper levels. The feet shuffled slightly on the metal floor, and he heard the little clicks of a locket being opened and closed.

"Mom's."

"Mm."

"I haven't done it before!"

"Because it does not work when I am not in the Core." He finally looked up, sighing as he looked down at Chara. "Why are you—"

"It wasn't on purpose, okay?" they said flatly, crossing their arms.

"Er, what?"

"What happened with Dad. I didn't want to hurt him."

Gaster looked at them in surprise, then turned back to the gauge. "I did not say anything regarding what happened with your father."

"Yeah, but you thought it."

"I did not."

Chara huffed, walking over to the railing. "It was just supposed to be _funny._ "

Gaster blinked. "Funny?"

Chara glanced up at him, dark eyes serious. "Y'know, buttercups instead of cups of butter. He'd think he was eating a butterscotch pie, but get a mouthful of flowers instead. I didn't think they'd _poison_ him." They leaned against the railing, looking down at the magma below them.

Gaster sighed as he shut the gauge's case. "You should go home and to bed, Chara. Today has been hard."

" _You_ aren't in bed."

"And when you are an adult, you can also manage stress in unhealthy ways." He sighed and rubbed his skull. "Why are you here? I do not think you would willingly hurt your father, so there is no need to plead your case."

Chara stayed quiet for a long moment, then dug in their pocket and pulled something out. Gaster leaned over curiously as he heard the crinkle of a wrapper.

"Is that…candy?" he asked with a frown. Chara nodded.

"Yeah, chocolate from the Surface. Mom got it for me." They broke a chunk of it off, then frowned and threw it down into the magma below.

" _Chara!_ "

They looked up. "Will it hurt the Core?"

"Er…" Well…it probably evaporated before any damage could be done, honestly. "No. But…if that's from the Surface, then it must be very hard to get, and you should not…"

"It doesn't matter." They broke off another chunk and tossed it down. "Mom'll get me more, somehow. She always does." They scowled, breaking off a bit more. "I didn't even say I wanted it. I just said it was the one thing I kinda missed." They heaved it down with a little grunt. "And y'know what happened when I said _I_ put the buttercups in the pie? Mom just said 'Oh, you did not mean to' and patted my head." They gritted their teeth as they threw down another piece. "I didn't get in trouble! I didn't even get _yelled at_ , and I almost killed Dad!" They pulled out the last piece of chocolate and heaved it down with a yell trapped behind clenched teeth. "It's no wonder you guys got pushed down here! Monsters let _anyone_ step all over them!"

Gaster couldn't do anything but stare at Chara as they screamed their frustrations down toward the Core. Well, this did explain some of their…recent developments. His hands fluttered as he tried to find what to say.

"Chara, they are trying to make things easier on you…"

"No! Shut up!" Chara gripped their head with a frustrated noise. "You're just saying what Mom and Dad want you to say! You think the same thing I do!"

Gaster blinked, then let out a breath. "No," he said evenly, "I do not."

Still holding their head, Chara let out a little whine. "Don't lie. You're the _only one_ who doesn't lie." Their voice had quieted into a whisper. "Monsters won't fight. Even when they need to, they _don't._ " They looked up at him, dark eyes wide. "I really could kill them all. And they'd probably _still_ tell me it wasn't my fault."

Gaster sighed. Slowly, reluctantly, he reached a mangled hand out to touch Chara's trembling shoulder.

"You would not intentionally hurt them. It is…not in your nature."

"God, stop _lying!_ " Chara pleaded. "I'm human, I know that! I've got Determination and…and that makes me dangerous!" They looked up at him, narrow chest heaving as they took several deep breaths. "I want to _help._ I want to break the Barrier and get monsters back on the Surface. But…but why should I help those who…who just make things harder? Why should I help anyone who brushes off the bad things humans do because it might hurt my feelings?"

"Because it is the kind thing to do," Gaster said without hesitation.

"I don't wanna do the kind thing, I wanna do the _right thing!_ " Chara snapped, tugging their shoulder out of Gaster's grip. _"_ And it's…it's stupid that they're trying to get in my way!"

Gaster pulled his hand back, watching Chara warily. When they remained quiet, he rubbed his skull again before meeting their gaze. "Chara. It has been a…a rough few months, and I understand. I _do_ ," he said firmly as Chara opened their mouth to argue. "You want me to be honest? Then I will be. I would like _nothing more_ than to study Determination further and try to find a way to use it to break the Barrier. But your parents do not want me causing you any…undue stress. So, because I respect them and I respect your own peace of mind, I have done as they asked and cancelled my remaining experiments."

He kept eye contact with them for a moment longer, then leaned against the railing with a sigh, looking up above them in slight exasperation. "When you are grown, you, Asriel, and I can discuss what is to be done about the Barrier, and if we would like to pursue anything further with Determination. But for now, we _both_ will follow what your parents have said."

He looked back over to Chara, who was now shooting him an impressively cold glare. However, after a moment, they sighed and walked back to the railing, hopping up to sit on it.

"Asriel will agree with it," they mumbled. "He agrees with me now. He wants to help."

"Yes, well, there is not much two children can do against complicated wizardry," Gaster said shortly.

"Actually, if…" they started, but as Gaster stared down hard at them, they looked back down at the magma. "Nevermind." They rested their chin on the metal bar, staring down below.

For a long while, the two were silent, merely staring down at roiling magma below, Chara contemplatively and Gaster worriedly. This was…concerning, to say the least. Not only Chara's attitude, but an outburst like this only reminded him of the frenzy they had worked themself into during the test. As much as Toriel and Asgore didn't want to admit it, Chara had every potential to be dangerous. They had to take every precaution to…

"Do you think a lot about the scientists who died?"

Gaster blinked, the question completely throwing his thoughts out of his mind. "Er, beg pardon?"

Chara's brow furrowed. "Y'know, in the explosion. Do you think about them?"

"Y…yes, of course."

"Did you ever think that they _needed_ to die?"

Gaster gaped. It took all his effort to force enough air out to ask, " _What_?"

"I mean, it was a safety issue that killed them, right? Well, if they hadn't died, maybe you wouldn't have fixed the Core, and then a whole bunch of people might've died." Chara shrugged. "So…it might be a good thing that only seven scientists did instead."

Gaster stared down at them with wide sockets. He wasn't sure what was more horrifying: the fact that Chara could even _suggest_ that the interns' deaths were a good thing, or that…the logic was fairly sound. He stayed very still for a long moment, then huffed a breath through his nasal cavity as he turned his head away.

"How old are you again?" he finally asked.

"Eleven."

"Sometimes it is hard to believe you are so young." He shook his head. "Death is never good. The interns were _people_ , with families and hopes. And they…"

"And they kept those families safe in the end. And that's good, isn't it? I…I think it is." They brought their head up and looked straight ahead, brow furrowed thoughtfully as the magma once again turned their dark eyes red. After a moment, their face relaxed, and they sent a smile up at Gaster.

"Guess that got a little dark, huh?" They swung their legs around to stand up. "Thanks for the talk, Dr. Gaster."

Gaster's head was reeling from the child's abrupt change in demeanor. "Chara, wait…"

They shook their head. "I'm sorry," they said, fiddling with the clasp of their locket again. "I…Dad being so sick kinda shook me up. I didn't mean to…to freak out so much."

"It is…all right." He clenched his jaw slightly. He didn't _want_ to offer this, but…well. It may be for the best. "Chara, if you would like…it would be all right if you wanted to talk to me about…Determination or anything along those lines. If you would like someone to speak frankly to you about it."

Chara smiled up at him. "You don't want to, but that's okay. I think I can figure things out on my own. I should head back home." They turned and started walking to the stairs. They paused, though, and glanced back at Gaster. "Dr. Gaster?"

"Er, yes?"

"If I was a monster, d'you think you would've liked me?"

Gaster was immediately about to deflect, but…well. Even if Chara was a human—a potentially dangerous one, even—it seemed he was their only source of honesty. He shrugged.

"I do not know. Possibly, yes."

Chara sent a smile his way.

"Thanks for being honest, Dr. Gaster. I really appreciate it."

* * *

Life progressed as usual. For a boss monster, Asgore's recovery was slow, but soon enough, he was back to full health. As far as Gaster knew, the only lasting effect from the poisoning was that his stomach got a bit sour from time to time.

As for Gaster himself, he and the Dreemurrs mended their friendship. Toriel admitted at that her feelings had gotten the best of her; Gaster insisted the fault was with him for pressing his own agenda into their family. All restrictions were lifted, and all notes on Determination went into the bin.

Even the children were doing better. Chara was behaving much better, and Asriel, of course, continued following them throughout all of their adventures without worry of being called a crybaby.

Things were going remarkably well, all things considered.

By the time all was friendly and Asgore was completely well, it was time for another Monster celebration. Gaster couldn't be bothered to find out which one it was, but all the same, he was a little glad to be invited again. He'd found himself missing these gatherings, strangely enough.

So, as Asgore spoke to the crowds, Toriel, the children, and Gaster all stood dutifully behind. Toriel, for some reason, kept patting Chara's hair and murmuring to them. Their normally rosy cheeks were pale, and their gaze was a little glassy; perhaps they had caught some strain of flu. Or, given the way they were twirling a stem aimlessly between their fingers, they were just bored, and Toriel was trying to keep them engaged. Gaster paid them no mind.

That is, until Chara collapsed.

There was a great uproar, and all eyes turned to the human child as they convulsed on the stage. Their hands reached up to their throat, trying to scratch at it. Toriel quickly grabbed Chara's hands to stop them from harming themself, then looked up at Gaster in fright.

"We must take them home," she said quickly, trying to pull the twitching child into her arms as Asriel backed up to clutch at his father. Asgore stared down at the scene in horror.

"Ch-Chara…" he wheezed out as Asriel whimpered. He looked over to Gaster, who felt frozen in place as he saw the scene unfold. "Gaster, you…you must…"

Gaster broke from his daze, and he nodded swiftly as he waved his hands. "Yes. I will. _Go_ , the both of you! I will do what I can!"

As Toriel picked Chara up, Gaster was off to the Lab, brain working at lightning speed. What _was_ that? How could they get _this_ ill so suddenly? This wasn't his area. He wasn't a healer.

But he _was_ a scientist. As he nearly catapulted himself in the Lab, he tried to think back to Chara's symptoms. Convulsing…had their throat been irritated? It must have been, given how they clawed at it. Why were those symptoms familiar? He hit his skull as his mind kept going back to the little stem they twirled, as if that would…

Oh.

Oh, god, _no._

He wasted no time in grabbing what he needed. IV bags—on hand just in case Asgore had relapsed—needles, antiseptic, chemical wash bottles…everything that _could_ be used to flush out toxins, he gathered up in his arms and carefully balanced as he ran back to New Home.

He had to be quick.

If he wasn't, Chara's decision would be irreversible. There would be no way for the Dreemurrs to recover from that, and the Underground would spiral into chaos.

* * *

He practically kicked the door to the Dreemurr household open. He wasted no time in looking for Toriel or Asgore, instead heading straight to the children's room. Chara had considerably less mass than Asgore, so if they had ingested—

He came to a dead stop as he saw a cloaked figure in Chara's room. The quiet _"Tra la la_ " they crooned over the child was enough to give away who they were.

"Who…What…" he tried to stammer out, but was interrupted as someone grabbed his arm.

"Thank god, you are here." Toriel looked up at Gaster. "The Riverperson has been able to keep them stable, but even they are not equipped for a human."

"Not eq…why are they even _here_?"

"There is no…" Toriel huffed as she saw the indignant look in Gaster's sockets. "In so many words, they are one of the best healers in the Underground. They say they even healed you." She let go of Gaster's arm to walk over to the Riverperson. She murmured something to the hood, which turned to look straight at Gaster. He felt something inside him squirm as their last words to him echoed in his head.

 _Beware the man who speaks in hands._

He shook his head. No. Not now. All of his focus had to go to saving Chara. He pushed past the Riverperson and headed straight into their room, shutting the door behind him. He took a breath as he looked at the nearly-lifeless child laying on the bed.

No time to doubt himself. He needed to _work._

IV was first. He set up a makeshift stand with a lamp and coat hanger, then hung the bag on there before inserting it, as carefully and quickly as possible, into Chara's arm before taping it down. He let out a breath; hopefully that would flush things out, but there was still other work to be done. He turned away to grab a small tube, just in case they needed to breathe if they vomited.

He turned to insert the tube, but stopped in surprise as he saw the IV had been taken out. Had he not secured it right? He inserted it again, then turned to grab a new piece of tape.

It was out again.

Was he this incompetent? He picked up the needle and positioned it right. Just as he started to push it back in, a small hand touched his arm.

"Dr. Gaster…"

Gaster jumped at the soft, rasping voice. He looked down with wide sockets as Chara forced their eyes open and gave him a smile.

"Please…let me die."

He felt his whole world freeze in this moment. The hand on his arm tightened.

"This is what we both want…" Despite the obvious pain they were in, Chara sent him a beatific smile, one of the biggest ones he'd seen from the child. "I heard you when I first fell down. You wanted to get rid of me. I…" A convulsion ripped through them, making them choke. Gaster winced as their hand tightened around his ulna nearly hard enough to snap it.

"No…No, that is not what I aim to do. Hold still," he muttered, carefully pulling their hand away. "Dying is never good."

"B-bu-but it _is!_ " The smile was back, splitting their dry lips in places, and their dark eyes shown brightly—from their sickness or their joy at dying, he wasn't sure. "It's _necessary._ A-A-Asriel and I…we're gonna break the barrier! We're gonna kill all the humans!" They let out a long, delirious laugh. "We planned it all!"

The hand was back on his ulna, gripping it hard. "And…and you get to help, Dr. Gaster!" They met his sockets with too wide eyes. " _Please._ Trust me. We're going to make the hu-humans p-pa-." They were cut off as their body was wracked by a series of sharp coughs; Gaster flinched as blood spattered from their mouth onto him. Once they finished, they trembled as they watched him, a few streams of blood trickling down their chin. " _Help me. Trust me._ "

Gaster stared down at them in horror; Chara looked expectantly at him. Finally, he let out a huff.

"I have not been able to trust you since the moment you fell down," he said shortly. "And I am not going to start now." He grabbed their arm and forced it away from his own. He jabbed the needle in and held it himself. "You _will_ be healed, Chara Dreemurr. I will not have your delusions of grandeur ruin my friends' lives."

Chara trembled as they looked up at him, eyes flashing. "I'm doing this with or without you, Dr. Gaster," they said, a sudden clarity in their voice as they glared into his sockets. "But I'm warning you: _don't get in my way._ "

Gaster stared down at them, then clenched his jaw. He held the needle in tighter.

Chara stared down at the scientist's hold on them, and their chest shuddered. After a few moments, the shuddering turned into a rasping laugh.

"Is this really what you want?" they asked. Their blood-stained mouth stretched, their eyes widened. Gaster immediately jumped back, needle coming with him, as Chara's face contorted into something straight out of a nightmare. They let out another screeching laugh.

" _I hope it was worth it._ "

All at once, their face was normal. They sent him one last smile, then let out a blood-curdling scream.

" _Mommy! Daddy! He's hurting me!_ "

Gaster sat, trembling, that horrific smile still fresh in his mind. He stayed frozen in place even as Chara convulsed on the bed, even as Asgore and Toriel burst into the room.

"He's hurting me! He…he wants my Determination!" Chara shrieked. Immediately, both Dreemurrs were by their side, trying to calm them down.

"Dr. Gaster is just…"

" _No!_ He _hurt_ me! Look at the blood!"

Asgore turned to look at Gaster, barely keeping his face in check as he saw the bloodstains on the Royal Scientist. "Gaster," he said tightly, "perhaps it's best if you go."

Gaster finally pulled himself from the shock. "N-no! You don't understand, they—"

" _Perhaps it is best if you leave_ ," Toriel said crisply, not looking at him.

"But I…" His hands moved; the blood made his phalanges stick. But ultimately, no words came from there or his mouth. Both the king and queen looked at him with hardened expressions. Behind them, Chara gave him a victorious, mocking smile.

Gaster closed his bloodstained hands into fists, then quickly left the room. As he left, he saw Asriel by the staircase to the Throne Room, his eyes wet. The prince sniffled and shrank back as he saw Gaster.

"Asriel," he said softly. "Please. Do not…"

Before he could say another word, there was another loud scream from Chara. Asriel whimpered, but quickly darted around Gaster and ran straight into the room. The door shut tightly behind him.

It looked as if he had no choice but to leave.

As he walked out of the house, he saw the Riverperson out of the corner of his eye, their hood moving to watch him. His shoulder stiffened, and his hands fluttered, but again, no words came. He quickened his step.

Perhaps, in a way, they were right.

It _was_ difficult to speak with blood on his hands.

* * *

He holed himself away in Snowdin for the next few days, avoiding any and all royal responsibilities for the moment. But even so, he heard what happened. The whole Underground had heard.

The child died. Asriel had absorbed their Soul. And, when he rose through the Barrier to lay Chara's body to rest, he was attacked by the Humans. The Throne Room, one of the local sentries said, was still covered in Asriel's dust.

And so, the entire Underground went into mourning. For the two Dreemurr children, for their parents' happiness, and for any hope the Monsters had of peacefully reaching the Surface.


End file.
